Host plants

Q&A

Host plants
Description

Pakistan

Prevention

Eradicate weeds from field in the beginning of the crop at early stage
Destroy the debris of the crop after harvesting
Grow only recommended varieties e.g. melon 1, sugarbaby, Ravi, T-96, Black Chairman, Jaguar, Black happy
Avoid sowing alternate host plants of white fly, like cabbage,cotton and okra, near melon crop

Monitoring

Attack of insects can be seen on leaves, flowers and tender branches
Infected plants look dirty and opaque
Sticky material comes from the body of insects and black fungus appears on leaves
Adults are small whitish flying insects and young ones are yellow dot like non-motile insects present on the underside of the leaves
Take action when 5 adults, young or both are observed per leaf (ETL)

Control

Promote the growth of beneficial insects (chrysoperla, ladybird beetle) by justifying the use of pesticides

Host plants
Description

Leafhoppers of the subfamily Idiocerinae are predominantly found on trees and shrubs. They are characterized by a broad rounded head, extending little between the eyes, and a general 'wedge' shape. According to Viraktamath (1989), 14 idiocerine species, in three genera (Amritodus, Busoniomimus and Idioscopus), breed on mango trees and of these only six are of economic importance. Unfortunately, there is no comprehensive taxonomic treatment available to separate all the mango-associated species.

Symptons

Nymphs and adults of Idioscopus species suck phloem sap from the inflorescences and leaves. The affected florets turn brown and dry up, and fruit setting is affected. Other effects of feeding are caused by honeydew on which sooty mould develops, affecting photosynthesis. Some damage may also occur through egg laying into the leaves and flower stems.

Hosts

I. nagpurensis is only known to attack mango trees, although it is also associated with other trees, at least in Sri Lanka (Gnaneswaran et al., 2007).

Host plant resistance

Presumably because of the time needed to grow mango trees large enough to test, there have been relatively few studies devoted to varieties resistant to attack by mango leafhoppers. Murthi and Abrahim (1983) investigated 12 mango varieties for population fluctuations of the hoppers during preflowering and postflowering periods by means of monthly sweeps of trees of uniform age. Progeny production by I. niveosparsus on floral branches was positively associated with the nitrogen content of the branches. Khaire et al. (1987) screened 19 varieties under field conditions for resistance to I. clypealis. In a study of the seasonal occurrence of mango leafhoppers, including I. nagpurensis, on a number of mango cultivars and hybrids in an orchard at Dharwad, Karnataka, India, cv. Baneshan and hybrid Neelgoa showed the lowest insect incidence (Shashidhar Viraktamath et al., 1996). Cultivars Baneshan and Khader and hybrids Neelgoa and Rumani were considered potentially useful in developing further resistant cultivars and hybrids.

Biological Control
To date there have been few studies where biological control has been attempted against mango leafhoppers. Several fungal pathogens may prove useful for biological control as mentioned by Kumar et al. (1983).

Source: cabi.org
Host plants Xanthomonas citri
Description


Phenotypic Characteristics
X. citri is a Gram-negative, straight, rod-shaped bacterium measuring 1.5-2.0 x 0.5-0.75 µm. It is motile by means of a single, polar flagellum. It shares many physiological and biochemical properties with other members of the genus Xanthomonas. It is chemoorganotrophic and obligately aerobic with the oxidative metabolism of glucose. Colonies are formed on nutrient agar plates containing glucose and are creamy-yellow with copious slime. The yellow pigment is xanthomonadin. Catalase is positive, but Kovacs' oxidase is negative or weak;nitrate reduction is negative. Asparagine is not used as a sole source of carbon and nitrogen simultaneously;various carbohydrates and organic acids are used as a sole source of carbon. Hydrolysis of starch, casein, Tween 80 and aesculin is positive. Gelatine and pectate gel are liquefied. Growth requires methionine or cysteine and is inhibited by 0.02% triphenyltetrazolium chloride. Biovars may be distinguished by utilization of mannitol. For further information on the bacteriological properties of X. citri, see Goto (1992).
Strains of groups B, C and D have many properties in common with group A, the differences being detected by the utilization of only a few carbohydrates (Goto et al., 1980).
Molecular Characterization
Features of citrus-attacking xanthomonads including X. citri and the genus Xanthomonas as a whole, have been characterized at the molecular level for the development of quick and accurate methods for reclassification and identification. The procedures include DNA-DNA hybridization (Vauterin et al., 1995), genomic fingerprinting (Lazo et al., 1987), fatty acid profiling (Yang et al., 1993), SDS-PAGE (Vauterin et al., 1991) and isoenzyme profiles (Kubicek et al., 1989) and monoclonal antibodies (Alverez et al., 1991).
Bacteriophages
Phage-typing is applicable to X. citri with greater reliability than any other plant pathogenic bacterium investigated so far. Many strains of X. citri are lysogenic (Okabe, 1961). Two virulent phages, Cp1 and Cp2, can infect 98% of the strains isolated in Japan (Wakimoto 1967). Similar results were also obtained in Taiwan (Wu et al., 1993). The filamentous temperate phages and their molecular traits have been studied in detail (Kuo et al., 1994;Wu et al., 1996). Phage Cp3 is specific to the canker B strains (Goto et al., 1980). No phages specific to canker C and D strains have been isolated.

Recognition


Methods of detecting X. citri from natural habitats include leaf-infiltration, bacteriophage, fluorescent antibody and ELISA (Goto, 1992). The polymerase chain reaction and dot blot immunobinding assay (DIA) were developed for rapid, sensitive, and specific detection of the pathogen. The detectable limits were reported to be around 30 c.f.u./ml for the former and 1000 c.f.u./ml for the latter (Hartung et al., 1993, 1996;Wang et al., 1997;Miyoshi et al., 1998).

Symptons


Canker lesions begin as light yellow, raised, spongy eruptions on the surface of leaves, twigs and fruits. The lesions continuously enlarge from pin-point size over several months and can be of many different sizes based on the age of the lesion. As the lesions enlarge, the spongy eruptions begin to collapse, and brown depressions appear in their central portion, forming a crater-like appearance. The edges of the lesions remain raised above the surface of host tissue and the area around the raised portion of the lesion may have a greasy appearance. The lesions become surrounded by characteristic yellow halos. Canker lesions retain the erupted and spongy appearance under dry conditions, such as in a greenhouse;whereas they quickly enlarge and turn to flat lesions with a water-soaked appearance with frequent rain. Canker lesions vary in maximum size from 5 to 10 mm, depending on the susceptibility of the host plant. The symptoms are similar on leaves, fruit and stems.
Canker lesions are histologically characterized by the development of a large number of hypertrophic cells and a small number of hyperplastic cells. At an early stage of infection, the cells increase in size and the nuclei and nucleoids stain more easily;there is also an increase in the amount of cytoplasm synchronized with rapid enlargement. However, these hypertrophied cells do not divide;cell division is only detected in the peripheral areas of lesions adjacent to healthy tissue.
The lesions of canker B, C and D are similar in appearance and histology to those of canker A (Goto, 1992).
Reddy and Naidu (1986) reported canker lesions on roots;however, this has not been confirmed.

Impact

X. citri is a bacterial pathogen that causes citrus canker - a disease which results in heavy economic losses to the citrus industry worldwide either in terms of damage to trees (particularly reduced fruit production), reduced access to export markets, or the costs of its prevention and control. Lesions appear on leaves, twigs and fruit which cause defoliation, premature fruit abscission and blemished fruit, and can eventually kill the tree. It is introduced to new areas through the movement of infected citrus fruits and seedlings, and inadvertent re-introduction is highly likely despite the quarantine restrictions that are in place in many countries. Locally, X. citri is rapidly disseminated by rainwater running over the surfaces of lesions and splashing onto uninfected shoots;spread is therefore greatest under conditions of hight temperature, heavy rainfall and strong winds. Some areas of the world have eradicated citrus canker, others have on-going eradication programmes, however, this pathogen remains a threat to all citrus-growing regions.

Hosts


The Citrus species listed in the table of hosts, and the following hybrids, are natural hosts of X. citri, with varying degrees of susceptibility to X. citri. In addition to host plant, susceptibility is also affected by the plant part affected, whether leaves, fruits or twigs. Reddy and Naidu (1986) reported canker lesions on roots but this has not been confirmed.
Hybrids:
C. aurantiifolia x Microcitrus australasica (Faustrime), C. limon x M. australasica (Faustrimon), C. madurensis x M. australasica (Faustrimedin), C. sinensis x Poncirus trifoliata (Citrange), C. paradisi x P. trifoliata (Citrumelo) (Schoulties et al., 1987), C. aurantifolium x P. trifoliata (Citradia), C. nobilis x P. trifoliata (Citrandin), C. unshiu x P. trifoliata (Citrunshu), Citrange x P. trifoliata (Cicitrangle), C. adurensis x Citrange (Citrangedin), C. deliciosa x Citrange (Citrangarin), C. unshiu x Citrange (Citranguma), Fortunella margarita x Citrange (Citrangequat), F. japonica x C. aurantiifolia (Limequat), C. maxima x C. aurantiifolia (Limelo), C. madurensis x C. aurantiifolia (Bigaraldin), C. maxima x C. sinensis (Orangelo), F. margarita x C. sinensis (Orangequat), C. nobilis (Clementine) x C. maxima (Clemelo), C. nobilis (King of Siam) x C. maxima (Siamelo), C. unshiu x C. maxima (Satsumelo), C. deliciosa x C. maxima (Tangelo), C. nobilis (King of Siam) x C. sinensis (Siamor), C. deliciosa x C. madurensis (Calarin), C. unshiu x C. madurensis (Calashu). C. aurantiifolia x F. marginata is immune (Reddy, 1997).
Other than Citrus species and their hybrids, most plants, except P. trifoliata, are not sufficiently susceptible to X. citri under natural conditions to warrant attention as hosts of the bacterium. Although the potential of these plants as natural hosts seems to be negligible, further investigation is necessary because no confirmative host surveys have been undertaken since the 1920s. Species names within the genus Citrus also merit some attention due to their inconsistent use by authors.
Plants other than Citrus spp.:
Unless otherwise stated, the following plants refer to Peltier and Frederich (1920, 1924) who defined susceptibility on the basis of artificial inoculation in the greenhouse (G) and/or in the field (F): Aeglopsis chevalieri (G), Atalantia ceylonica (G), Atalantia citrioides (G), Atalantia disticha (G) (Lee, 1918), Chalcas exotica (G), Casimiroa edulis (G, F), Chaetospermum glutinosum (G, F), Clausena lansium (G), Citropsis schweinfurthii (G), Eremocitrus glauca (G, F), Evodia latifolia (G), Evodia ridleyei (G), Feronia limonia [ Limonia acidissima ] (G), Feroniella lucida (G, F), Feroniella crassifolia (G), Fortunella hindsii (G, F), Fortunella japonica (G, F), Fortunella margarita (G, F), Hesperethusa crenulata (G, F), Lansium domesticum (G), Melicope triphylla (G), Microcitrus australasica (G, F), Microcitrus australasica var. sanguinea (G, F), Microcitrus australis (G, F), Microcitrus garrowayi (G, F), Paramignya monophylla (G), Paramignya longipedunculata (G) (Lee, 1918), Poncirus trifoliata (G, F), Xanthoxylum clava-herculis [ Zanthoxylum clava-herculis ] (G, F), Xanthoxylum fagara [ Zanthoxylum fagara ] (G, F) (Jehle, 1917). Atalantia ceylanica, A. monophylla, Microcitrus australis, Feronia limonia and Severinia buxifolia are immune (Reddy, 1997). In India, goat weed (Ageratum conyzoides) is reported to be a host (Pabitra et al., 1997) but confirmation is needed.
The following plants have also been reported as susceptible to X. citri, however, the original descriptions were either not confirmed (U) or contradict those of other authors (C): Aegle malmelos (C), Balsamocitrus paniculata (U), Feroniella obligata (U), Matthiola incana var. annua (U) and Toddalia asiatica (C).
Of the primary hosts listed, yuzu is highly resistant (Goto, 1992) and calamondins, Cleopatra mandarin and Sunki mandarin are immune (Reddy, 1997). Both Fortunella japonica and F. margarita are highly resistant (Goto, 1992).


Source: cabi.org
Host plants Striga asiatica
Description

S. asiatica is not a conspicuous weed;it had spread to infest almost 200,000 hectares before being noticed in the USA. There is nothing about the shoot system of S. asiatica to suggest that it is a parasite. The height of the weed is variable, but rarely exceeds 30-40 cm, while some forms may be no more than a few centimetres high. Most other morphological characters are also variable. In vigorous plants there may be many branches, while small individuals or ecotypes may be unbranched. Length of the normal-looking green leaves may vary from 1 to 5 cm but leaf shape is generally narrowly lanceolate. Stem and leaves are sparsely covered in scabrid hairs.

Recognition


Where infestation is suspected, from previous history or from unexpected wilting symptoms, uprooting the crop can reveal the small white seedlings of S. asiatica on the roots, but the attachments are very fragile and gently washing the roots out of the soil will ensure a better chance of finding them.
A technique for detecting the seeds of S. asiatica as contaminants of crop seed is described by Berner et al. (1994). This involves sampling the bottom of sacks, elutriation of samples in turbulent flowing water and collection of seeds and other particles on a 90 µm mesh sieve. Striga seeds are then separated from heavier particles by suspension in a solution of potassium carbonate of specific gravity 1.4 in a separating column. Sound seeds collected at the interface are then transferred to a 60 µm mesh for counting.

Symptons


The symptoms of attack by S. asiatica may be apparent some time before the weed emerges, hence, the common name 'witchweed'. At an early stage, these symptoms are indistinguishable from those caused by drought, i.e. wilting and curling of the leaves, but they are strong indicators of S. asiatica if they occur when the soil is still moist. The infected plant may also show stunting from quite an early stage and pronounced scorching of the leaf borders and finally of the whole leaf area may occur at a later stage, hence, the common name 'fireweed' and equivalents in other languages.
As shoot growth is reduced, root growth is increased in plants infected by S. asiatica (Patterson, 1990).

Impact

S. asiatica is a hemiparasitic plant, native to Africa and Asia. In common with most other parasitic weeds, it is not especially invasive in natural vegetation, but is much feared in crop land where infestations can build up to ruinous levels, especially with repeated growing of susceptible cereal crops. For this reason it is included in almost all lists of noxious, prohibited plant species. It has recently been reported in Queensland, Australia. There is also evidence for its continuing spread and intensification within a number of countries in Africa in particular in rice in Tanzania and maize in Malawi. A study by Mohamed et al. (2006) suggests that on the basis of climatic data, there are many territories into which Striga species, including S. asiatica, could be introduced and thrive. Global warming could further increase this potential.

Hosts

S. asiatica is an obligate parasite and cannot develop without a suitable host plant. Apart from the major crops including sorghum, maize, pearl millet, finger millet, Panicum millets and rice, a wide range of wild hosts are parasitised. For the USA, these are listed by Nelson (1958), the most common being the weed Digitaria sanguinalis. There are many other wild hosts in Africa and Asia. Those recorded up to 1956 are listed in McGrath et al. (1957). Some further host species almost certainly include Andropogon gayanus, Axonopus compressus, Chrysopogon acicularis [ C. aciculatus ], Digitaria smutsii [ D. eriantha ], Eleusine indica, Elionurus elegans, Eragrostis malayana [ Eragrostis montana ], Ischaemum indicum [ Polytrias indica ], I. timorense, Microchloa indica, Rottboellia cochinchinensis, Sporobolus festivus and Stenotaphrum dimidiatum (synonym S. secundatum). Further hosts are listed by Cochrane and Press (1997). A number of broad-leaved hosts are recorded in McGrath et al. (1957) but occurrence on anything other than Poaceae is quite rare and some records may be suspect. Due to the very fragile connection between host and parasite it is often difficult, in a mixed grass community, to identify the host with any certainty.
There are distinct ecotypes of S. asiatica with different host specificity and each form may have quite limited host range. Botanga et al. (2002) describe a range of forms in Benin, including red- and yellow-flowered types with differing virulence on maize and sorghum but do not ascribe sub-specific names to these forms. Hence, there are many regions in Africa and Asia where the species occurs but is restricted to wild hosts and does not affect crops.

Biological Control
Organisms considered to have potential as biocontrol agents for S. asiatica and/or other Striga species have included the gall-weevil, Smicronyx spp. the agromyzid fly, Ophiomyia Strigalis, the moths, Eulocastra argentisparsa and Eulocastra undulata, the plume moth, Stenoptilodes taprobanes, the powdery mildew Sphaerotheca fuliginea and other fungi including Drechslera longirostrata, Phoma and Cercospora species (Greathead, 1984). Evans (1987) considered Cercospora strigae the most promising of the fungi. Several different species of Fusarium have been shown to have potential against both S. hermonthica and S. asiatica (Abbasher et al., 1995;1996). None of these organisms have yet been successfully utilised, but the possibilities for using Fusarium oxysporum are still considered promising (Beed et al., 2007). The strain Foxy 2, widely tested on S. hermonthica is confirmed also to be active against S. asiatica (Elzein et al., 2002). More virulent strains are now being tested along with a novel means of on-farm culturing and it is hoped there could be commercialisation before too long (Koltai, 2015). The only attempts to control S. hermonthica have been with the introduction of Smicronyx albovariegatus and Eulocastra argentisparsa from India into Ethiopia in 1974 and 1978, but there is no evidence that these organisms ever established.

Source: cabi.org
Host plants Anguina tritici
Description

Measurements

Symptons

The absence of symptoms does not mean absence of A. tritici (Thorne, 1949). Slight elevations occur on the upper leaf surface with indentations on the lower side. Other symptoms include wrinkling, twisting, curling of the margins towards the midrib, distortion, buckling, swelling and bulging. A tight spiral coil evolves, and dwarfing, loss of colour or a mottled, yellowed appearance and stem bending may also occur (Byars, 1920;Leukel, 1924). In severe infection, the entire above-ground plant is distorted to some degree and a disease problem is usually obvious.
Heads (spikes)
Wheat heads are reduced with glumes protruding at an abnormal angle exposing the galls to view. This does not occur in rye heads.
Galls
Young galls are short-thick, smooth, light to dark green, turning brown to black with age, 3.5-4.5 mm long and 2-3 mm wide. Rye galls are small, buff-coloured and longer than wide, 2-4.5 mm long by 1-2.5 mm wide (Byars, 1920;Leukel, 1924).

Impact

Anguina tritici, commonly referred to as wheat seed gall nematode, is the cause of ear-cockle disease. It was the first plant-parasitic nematode to be described in the scientific literature in 1743. Its host range includes wheat, triticale, rye, and related grasses;the primary host is wheat. Ear cockle in the past was reported in all major wheat growing areas. However, physical and mechanical methods for separating infected galls from seed have eradicated the nematode from the western hemisphere. It remains a problem in several countries in the Near and Middle East, the Asian Subcontinent and Eastern Europe, most likely due to poor awareness and lack of campaigns for establishing clean seed. A. tritici is on the U.S. Pests of Economic and Environmental Importance List, and on the ‘Harmful Organism Lists’ for Argentina, Brazil, Chile, Colombia, Ecuador, Egypt, Guatemala, Indonesia, Israel, Madagascar, Namibia, Nepal, New Zealand, Paraguay, Peru, South Africa, Taiwan, Thailand, Timor-Leste and Uruguay.

Hosts

A. tritici is highly specialized with a narrow host range. Significant multiplication only occurs on wheat or closely related plants. Many common grasses have been exposed to A. tritici;most have been shown to be non-hosts (Leukel, 1957).
Oat and Polypogon monococcum are poor hosts (Southey, 1972). A. tritici invades and multiplies in maize tissue, but does not complete its life cycle in this plant (Limber, 1976).
In addition to the hosts listed in the table, Alopecurus monspeliensis and Lolium temulentum (Dahiya and Bhatti, 1980), Holcus lanatus and Phleum pratensis (Filipjev and Schuurmans Stekhoven, 1941), and Triticum monococcum (Southey, 1972) are also reported as hosts of A. tritici.

Biological Control
There are few reports concerning biological control of A. tritici.<br>Host-Plant Resistance<br>A large number of plants have been evaluated for resistance to A. tritici over a period of more than 60 years. A few resistant plants have been found, such as the wheat cultivar Kanred (Leukel, 1924);however, resistance does not appear to be a viable solution to the problem of seed gall nematodes.

Source: cabi.org
Host plants Erwinia amylovora
Description


Cells of E. amylovora are Gram negative rods, 0.3 x 1-3 µm in size, occur singly, in pairs and sometimes in short chains, and are motile by two to seven peritrichous flagella per cell (see Paulin, 2000, for review).
E. amylovora forms colonies of characteristic colour and colony formation on most culture media (Bereswill et al., 1998). Colonies are domed, circular, mucoid on sucrose nutrient agar (Billing et al., 1961);red to orange on MS medium (Miller and Schroth, 1972);white, circular, mucoid on KB medium (Paulin and Samson, 1973);smooth large, pulvinate, light blue opalescent with craters on CCT medium (Ishimaru and Klos, 1984);and yellow, highly mucoid or less mucoid on MM2Cu media (Bereswill et al., 1998).

Recognition


Water-soaked flowers, spurs, or shoot tips accompanied by ooze production, followed quickly by necrosis, are early symptoms of fire blight. These symptoms can be detected in an orchard or nursery by experienced observers, but may be overlooked by the inexperienced.
A suitable period for inspection is 3-5 weeks after the blossom period. Look for necrotic leaves and branches, withered blossoms, crooked shoot tips, and ooze. Ooze is more likely to be present in the morning when air humidity is high and host water potential is positive;later in the day when the air is dry, ooze may be shiny and glassy.
Cankers may form on branches and trunks at the junction between infected and healthy bark tissues;therefore, inspections may be needed every 5-7 days throughout the summer or until no new infections are observed.
In autumn, mummified fruits and leaves hanging on dead branches is an indication of fire blight. In winter, the debris helps in locating cankers since the darker bark associated with old infection can blend in with the dormant healthy bark, particularly on older trees.

Symptons


Fire blight's basic symptom is necrosis or death of tissues. Droplets of ooze on infected tissues are also an important symptom;they are the visible indication of the presence of fire blight bacteria. Except for minor differences, the symptoms of fire blight are basically the same on all host plants.
Infected blossoms initially become water-soaked and of a darker green as the bacteria invade new tissues. Within 5-30 plus days (commonly 5-10 days), the spurs begin to collapse, turning brown to black. Initial symptoms are often coincident with the accumulation of about 57 degree days, base 12.7°C, from the infection date (Steiner, 2000).
Infected shoots turn brown to black from the tip;shoots often bend near the tip to form a so-called 'shepherd-crook' shape. Shoots invaded from their base exhibit necrosis of basal leaves and the stem. Leaves and fruits may be invaded through petioles or stems or infected through wounds, resulting in discoloration followed by collapse of the leaves and fruit. During wet, humid weather, infected leaves and particularly the fruit often exude a milky, sticky liquid, or ooze containing bacteria.
From infected flowers and shoots, the bacteria may invade progressively larger branches, the trunk and even the rootstock. Infected bark on branches, scaffold limbs, trunk and rootstock turns darker than normal. When the outer bark is peeled away, the inner tissues are water-soaked often with reddish streaks when first invaded;later the tissues are dark brown to black. As disease progression slows, lesions become sunken and sometimes cracked at the margins, forming a canker.
Trees with rootstock blight may exhibit liquid bleeding from the crown at or just below the graft union in early summer. Water-soaked, reddish and necrotic tissues are visible when the outer bark is removed. Trees with infected rootstocks often exhibit yellow to red foliage about a month before normal autumn coloration. Rootstocks such as M.26, M.9 and relatives of M.9 often show these symptoms without evidence of infection in the trunk of the scion. Infection of M.7 and a few other rootstocks occurs following infection of suckers arising from the rootstocks;the infected suckers exhibit typical shoot blight symptoms. Many trees with rootstock blight will die in the first year after infection;the remaining rootstock-infected trees often die within 2-3 years.
Any plant tissues invaded by the bacteria can show ooze production on their surface. This exudate is a specific symptom of fire blight. Depending on weather conditions and on the time of the day, ooze may or may not be produced. It is most frequently observed early in the morning when the host water potential is positive. It may appear in different ways: droplets, threads or film on the plant's surface.

Impact


The long distance spread of fire blight is a rare event which in most cases seems to be the result of plants or plant tissues being moved across the oceans. Short distance spread is the result of the characteristics of the pathogen, especially its ability to produce an exudate (bacteria embedded in exopolysaccharides) which is easily transported by wind, rain, insects or birds. This is very efficient;once the pathogen has moved into a new territory it almost always colonizes and becomes established. This is accompanied by economic losses in regions where apple, pear or loquat are grown commercially;it might prevent the survival of local cultivars and could disrupt international trade. To date fire blight has colonized most of North America, Western Europe and most of the countries around the Mediterranean Sea as well as New Zealand. Outbreaks of fire blight are irregular and difficult to control.

Hosts

E. amylovora is a pathogen of plants in the family Rosaceae;most of the natural hosts are in the subfamily Maloideae (formerly Pomoideae), a few belong in the subfamilies Rosoideae and Amygdaloideae (Momol and Aldwinckle, 2000). Genera in the subfamily Spiraeoideae have been reported as hosts on the basis of artificial inoculation (van der Zwet and Keil, 1979).
Strains of E. amylovora isolated from one host are pathogenic on most other hosts. This was the case for strains isolated from natural infections on Prunus salicina in the USA (Mohan and Thomson, 1996) and on Prunus domestica and Rosa rugosa in southern Germany (Vanneste et al., 2002a). Rubus strains (see Taxonomy and Nomenclature) are host specific;they are pathogenic on brambles but not on apple and pear (Starr et al., 1951;Braun and Hildebrand, 2005). Also, a few Maloideae strains exhibit differential virulence on apple;for example, strain Ea273 was not pathogenic across the same range of apple cultivars and rootstocks as common strain E4001A (Norelli et al., 1984, 1986).
Within each group of susceptible host plants, species or cultivars may be found with a high level of resistance;such plants may show no, or limited, symptoms under natural conditions or even following artificial inoculation (Forsline and Aldwinckle, 2002;Luby et al., 2002). Lists of resistant cultivars are published for important crops (van der Zwet and Keil, 1979;Zeller, 1989;Thomas and Jones, 1992;Berger and Zeller, 1994;van der Zwet and Bell, 1995;Bellenot-Kapusta et al., 2002).
Wild Pyrus (P. amygdaliformis, P. syriaca) in southern Europe and in the Mediterranean area, Crataegus (C. oxyacantha [ C. laevigata ], C. monogyna) in northern and central Europe, and ornamentals (Pyracantha, Cotoneaster, Sorbus) throughout Europe are important sources of inoculum for apple and pear orchards.


Source: cabi.org
Description

R. solanacearum is a Gram-negative bacterium with rod-shaped cells, 0.5-1.5 µm in length, with a single, polar flagellum. The positive staining reaction for poly-ß-hydroxybutyrate granules with Sudan Black B or Nile Blue distinguishes R. solanacearum from many other (phytopathogenic) Gram-negative bacterial species. Gram-negative rods with a polar tuft of flagella, non-fluorescent but diffusible brown pigment often produced. Polyhydroxybutyrate (PHB) is accumulated as cellular reserve and can be detected by Sudan Black staining on nutrient-rich media or the Nile Blue test, also in smears from infected tissues (Anonymous, 1998;2006) On the general nutrient media, virulent isolates of R. solanacearum develop pearly cream-white, flat, irregular and fluidal colonies often with characteristic whorls in the centre. Avirulent forms of R. solanacearum form small, round, non-fluidal, butyrous colonies which are entirely cream-white. On Kelman’s tetrazolium and SMSA media, the whorls are blood red in colour. Avirulent forms of R. solanacearum form small, round, non-fluidal, butyrous colonies which are entirely deep red.

Recognition


The bacterium may be obtained from infected tubers or stems for staining purposes if a small portion of tissue is pressed onto a clean glass slide. Potato tubers can be visually checked for internal symptoms by cutting. Suspect tubers should be diagnosed in the laboratory. Appropriate laboratory methods to detect the pathogen have been laid down in a harmonized EU-interim scheme for detection of the brown rot bacterium (Anon., 1997). These methods are based on earlier described indirect immunofluorescence antibody staining (IFAS). Standard samples of 200 tubers per 25 t of potatoes are taken (Janse, 1988;OEPP/ EPPO, 1990a;Anon., 1997, 1998, 2006). Recently a very effective selective medium has been described (Engelbrecht, 1994, and modified by Elphinstone et al., 1996), that can also be applied for detection in environmental samples such as surface water, soil and waste (Janse et al., 1998;Wenneker et al., 1999). ELISA and PCR, based on 16S rRNA targeted primers as well as fluorescent in-situ hybridization (FISH) using 16S and 23S rRNA-targeted probes have also been used.
Ralstonia syzygii, causal agent of Sumatra disease of clove (Syzygium) and the distinct Blood Disease Bacterium, causal agent of blood disease of banana in Indonesia, are closely related to R. solanacearum and cross-react in serological and DNA-based detection methods (Wullings et al., 1998;Thwaites et al., 1999).

Symptons


Potato
Foliage: the first visible symptom is a wilting of the leaves at the ends of the branches during the heat of the day with recovery at night. As the disease develops, a streaky brown discoloration of the stem may be observed on stems 2.5 cm or more above the soil line, and the leaves develop a bronze tint. Epinasty of the petioles may occur. Subsequently, plants fail to recover and die. A white, slimy mass of bacteria exudes from vascular bundles when broken or cut.
Tubers: external symptoms may or may not be visible, depending on the state of development of the disease. Bacterial ooze often emerges from the eyes and stem-end attachment of infected tubers. When this bacterial exudate dries, soil masses adhere to the tubers giving affected tubers a 'smutty' appearance. Cutting the diseased tuber will reveal browning and necrosis of the vascular ring and in adjacent tissues. A creamy fluid exudate usually appears spontaneously on the vascular ring of the cut surface.
Atypical symptoms on potato (necrotic spots on the epidermis), possibly caused after lenticel infection, have been described by Rodrigues-Neto et al. (1984).
Symptoms of brown rot may be readily distinguished with those of ring rot caused by Clavibacter michiganensis subsp. sepedonicus (EPPO/ CABI, 1997). R. solanacearum can be distinguished by the bacterial ooze that often emerges from cut stems and from the eyes and stem-end attachment of infected tubers. If cut tissue is placed in water, threads of ooze are exuded. Because such threads are not formed by other pathogens of potato, this test is of presumptive diagnostic value. For ring rot, tubers must be squeezed to press out yellowish dissolved vascular tissue and bacterial slime.
Tomato
The youngest leaves are the first to be affected and have a flaccid appearance, usually at the warmest time of day. Wilting of the whole plant may follow rapidly if environmental conditions are favourable for the pathogen. Under less favourable conditions, the disease develops slowly, stunting may occur and large numbers of adventitious roots are produced on the stem. The vascular tissues of the stem show a brown discoloration and drops of white or yellowish bacterial ooze may be released if the stem is cut (McCarter, 1991).
Tobacco
One of the distinctive symptoms is partial wilting and premature yellowing of leaves. Leaves on one side of the plant or even a half leaf may show wilting symptoms. This occurs because vascular infection may be restricted to limited sectors of stems and leaf petioles. In severe cases, leaves wilt rapidly without changing colour and stay attached to the stem. As in tomato, the vascular tissues show a brown discoloration when cut. The primary and secondary roots may become brown to black (Echandi, 1991).
Banana
On young and fast-growing plants, the youngest leaves turn pale green or yellow and collapse. Within a week all leaves may collapse. Young suckers may be blackened, stunted or twisted. The pseudostems show brown vascular discoloration (Hayward, 1983). Moko disease, caused by R. solanacearum, is easily confused with the disease caused by Fusarium oxysporum f.sp. cubense. A clear distinction is possible when fruits are affected - a brown and dry rot is only seen in Moko disease.
Teak
Seedling wilt manifests itself as yellowing of the mature lower leaves, which show scorching and browning of the tissue between the veins. The younger leaves and terminal shoot become flaccid and droop. Affected seedlings show either a gradual loss of leaf turgidity or sudden wilting. Seedling wilt becomes evident in the early hours of the day and gradually becomes more pronounced by midday, especially on sunny days. The wilted seedlings may partially recover during the afternoon and evening when temperatures fall, but wilting becomes more pronounced on successive days. The roots of affected seedlings exhibit a brownish-black discoloration. In advanced stages of disease, the tuberous portion of the root becomes discoloured and spongy. In due course, seedlings with pronounced wilt symptoms become completely desiccated.
In container nurseries, R. solanacearum infects the cotyledons of emerging seedlings causing greyish-brown, water-soaked lesions, which spread to the entire cotyledon and become necrotic. The infection spreads to the adjoining stem and root tissues and the affected seedlings rot and die. Collar rot appears in 1- to 4-month-old bare-root seedlings as greyish-brown, water-soaked lesions at the collar region of seedlings, just above the soil level. The lesions spread longitudinally on the stem, both above and below ground level, becoming sunken and necrotic. The younger leaves become flaccid and droop followed by leaf scorching and pronounced vascular wilt. In bare-root nurseries, wilt usually occurs in small patches affecting individuals or groups of seedlings, which expand as more seedlings succumb to the infection.
Infection of mature foliage begins as greyish-brown to greyish-black, irregular lesions that spread to the entire leaf lamina. Infection spreads to the petioles and stems.

Impact


The strains in the race 3 group are a select agent under the US Agricultural Bioterrorism Protection Act of 2002 (USDA, 2005). Peculiarly, the organism, if not yet already present in North America in pelargonium (Strider et al., 1981), was introduced with cuttings of this host by American companies producing these cuttings for their markets in countries like Kenya and Guatamala (Norman et al., 1999, 2009;Kim et al., 2002;Williamson et al., 2002;Williamson et al., 2002;O’ Hern, 2004). A similar situation led to introductions of the pathogen from Kenya into some northern European nurseries. Once the source (contaminated surface water) was recognized and proper control measures (use of deep soil water, disinfection of cutting producing premises and replacement of mother stock), the problem was solved and the disease in greenhouses eradicated (Janse et al., 2004);Similarly race 1 has been introduced into greenhouses with ornamental plants (rhizomes, cuttings or fully grown plants) such as Epipremnum, Anthurium, Curcuma spp. and Begonia eliator from tropical areas (Norman and Yuen, 1998, 1999;Janse et al., 2006;Janse, 2012). Introduction can and did occur from Costa Rica and the Caribbean, Indonesia, Thailand and South Africa. However, this idea of placing pathogens on bioterrorist list for unclear and perhaps industry-driven reasons and its effects, is strongly opposed in a recent publication from leading phytobacteriologists. This is because R. solanacearum is an endemic pathogen, causing endemic disease in most parts of its geographic occurrence, moreover normal quarantine regulations are already in place where the disease is not present or only sporadically and are thought to be more efficient and less damaging to trade and research than placing this pathogen on select agent lists and treating it as such (Young et al., 2008). Peculiarly, it has been used in the control of a real invasive species, the weed kahili ginger (Hedychium gardenarium) in tropical forests in Hawaii. This is not without risks because strains occurring on this weed host were thought to be non-virulent, but later appeared to be virulent on many edible and ornamental ginger species as well (Anderson and Gardner, 1999;Paret et al., 2008). The earlier mentioned tropical strains belonging to phylotype II/4 NPB could become an emerging problem not only in the Caribbean, but also to Southern Europe and North Africa where higher yearly temperatures prevail. Another threat for these countries could be strains belonging to race 1, biovar 1 (phylotype I) that have already been reported from field-grown potatoes in Portugal (Cruz et al., 2008).

Hosts

R. solanacearum as a species has an extremely wide host range, but different pathogenic varieties (races) within the species may show more restricted host ranges. Over 200 species, especially tropical and subtropical crops, are susceptible to one or other of the races of R. solanacearum. Worldwide, the most important are: tomato, tobacco, aubergine, potato, banana, plantain and Heliconia. Within the EPPO region, race 3 (see Biology and Ecology) with a limited host range including potato, tomato and the weed Solanum dulcamara, is considered to have potential for spread.
Other host crops are: Anthurium spp., groundnut, Capsicum annuum, cotton, rubber, sweet potato, cassava, castor bean and ginger.
Many weeds are alternative hosts of the pathogen. Solanum cinereum in Australia (Graham and Lloyd, 1978), Solanum nigrum and, in rare cases, Galinsoga parviflora, G. ciliata, Polygonum capitata, Portulaca oleracea (for example, in Nepal;Pradhanang and Elphinstone, 1996a) and Urtica dioica have been reported as weed hosts for race 3 (Wenneker et al., 1998). S. nigrum and S. dulcamara are primary wild hosts for race 3.
Lists of host records have been recorded (Kelman, 1953;Bradbury, 1986;Persley, 1986;Hayward, 1994a) but the original reports, gathered over many years, vary greatly in reliability. Few reference strains from reported host plants have been deposited in publicly accessible culture collections to support the authenticity of records.


Source: cabi.org
Description


The shell of G. kibweziensis is translucent white, and dorso-ventrally distorted due to allometric changes during shell ontogeny. The juvenile shell is discoidal dome-shaped;the adult shell more globose and with the axis of coiling at about 13° angle to the axis of the juvenile. When the adult shell is examined in apertural view, the juvenile whorls sit atop and displaced to one side by the broader last two whorls of the adult whorls. Adult whorls with broadly rounded periphery. Aperture rounded, without barriers, with somewhat thickened and slightly reflected margins;parietal callus well developed. Umbilicus a minute perforation.The protoconch is smooth. The teleconch whorls are delicately ribbed.

Impact

G. kibweziensis is a non-specific predatory snail, taking a number of other snail species as prey. The species is not widely recognized as invasive. While it has become widely distributed in the islands of the Pacific and Indian Oceans as a biological control agent against giant African snails, continues to be spread in at least some regions by human agencies, and is known to interact with some native mollusc species, G. kibweziensis has not been unequivocally confirmed as threatening ecosystems, habitats or species or having major economic consequence.
Predation on native snails in regions to which G. kibweziensis has been introduced is undoubtedly occurring. Concern about G. kibweziensis effects on native land snail communities has been expressed in a number of countries to which the species has been introduced as a biological control agent, but definitive evidence for such effects is presently lacking. The use of generalized predators in biological control programs has long been recognized as unsafe due to expected environmental impacts, not least adverse effects on non-target species.

Biological Control
<br>Most natural enemies of terrestrial gastropods have proved not to be host-specific and therefore are not amenable for use in control programmes where effects on non-target species are of concern. To date, no natural enemy specific to G. kibweziensis is known.

Source: cabi.org
Description

The following description is from Flora of China Editorial Committee (2016)

Impact

D. bicornis is an annual, sometimes perennial grass. It is listed as invasive in North America (Mexico), Central America (El Salvador, Guatemala, Honduras, Nicaragua, Panama), the Caribbean (Cuba), South America (Colombia, Ecuador) and Oceania (Nauru, USA-Hawaii) (Catasús Guerra, 2015;PIER, 2016). It is considered as a weed in cultivated fields (Quattrocchi, 2006;Dias et al., 2007;Duarte et al., 2009;Catasús Guerra, 2015;Ramírez S et al., 2015).

Hosts

D. bicornis is a weed that occurs in maize, rice, soyabean and sugar cane fields (Quattrocchi, 2006;Dias et al., 2007;Ramírez S et al., 2015). Plants of maize and rice have been reported as being affected by downy mildew disease caused by Sclerophthora rayssiae that was acquired from soil where seedlings of D. bicornis were previously growing (Chamswarng et al., 1976).


Source: cabi.org
Description

Floating perennial aquatic plant, typically rooted in mud. Plant height up to 100 cm tall. Vegetative stems elongate, developing to and growing at water surface. Flowering stems erect, 8–12 cm, glabrous, distal internode 2–10 cm. Leaves submerged, floating or emergent (or a combination of any two). Sessile leaves submersed, no petiole, alternate on elongate stem. Petiolate leaves emersed;stipule 7–13 cm, apex truncate;petiole never inflated, 11–25 cm;blade round, 7–16 × 2.3–16 cm. Inflorescence a spike or panicle, subtended by 2 reduced, dissimilar leaves. Spikes 7–50-flowered sometimes carrying more than 60 flowers (Gopal, 1987). Flower zygomorphic, spathes obovate, 3–6 cm;peduncle 1.9–15 cm, pubescent with orange hairs. Perianth blue or white, limb lobes obovate, 13–25 mm, margins erose, central distal lobe dark blue at base with yellow distal spot (Haynes, 1988);proximal stamens 15–29 mm, distal 6–20 mm;anthers 1.2–2.3 mm;style 3-lobed. Seeds develop from an anatropous ovule. The fruit contains 10–13-winged seeds (Flora of North America, 2009) 1.5-2.6 mm long, 0.3-0.9 mm wide (Sher, 2009). The roots extend into the substrate, which length varies greatly;5 cm in the younger portions of the stems but can reach up to 1 m in the older portions (Padial et al., 2009).

Impact

E. azurea is a rooted perennial aquatic plant with submersed and emersed leaves. Several taxa of this family have spread, as weeds or ornamentals (Barrett, 1978), outside the limits of their native range (Eckenwalder and Barrett, 1986). Eichhornia crassipes is the species best known for its invasiveness;it is one of the most troublesome weeds in the world (Gopal, 1987) and is declared a noxious weed in many countries, including in the USA and in two states in Australia. The status of E. crassipes (water hyacinth) as a weed has led to the subsequent designation of E. azurea and several species of Eichhornia as prohibited imports in various countries (USDA-NRCS, 2016;The State of New South Wales, 2009).
E. azurea was introduced into the USA from South America as an aquatic ornamental in the 1980s. It has occasionally escaped into local environments in the USA (Gopal, 1987) but has not become established as a weed there. According to historical records, E. azurea has been reported in southern Florida and more recently in Texas (TexasInvasives.org, 2016). It has also been reported in Japan but possibly as a temporary occurrence only (Kadono, 2004).
E. azurea is a weed with a widespread distribution in Brazil, where it often creates large floating mats which obstruct navigation and many other uses of aquatic resources. Reproduction is by seed and vegetatively. Dispersal is by whole plants, by water or by birds.


Source: cabi.org
Description

T. domingensis is a rhizomatous perennial emergent wetland macrophyte. Ramets (culms) range from 1-6 m tall (Denny, 1985b) and consist of numerous slender, linear, distichous leaves with a sheathing base that emerge vertically from a central meristem. Ramets often produce a single, erect, monoecious flowering stem consisting of a staminate spike above a pistillate spike. At maturity, ramets can collapse from wind, or under their own weight (S Hall, University of Wisconsin, USA, personal communication, 2008). Rhizomes often measure several centimeters in diameter and produce abundant adventitious roots. Smith (1967, 2000) distinguished T. domingensis from similar species primarily on the basis of pistillate spike characters. T. domingensis is characterized by: pistillate bracteoles pale to light brown, slightly exceeding pistil hairs in mature spikes;pistil hair apices colorless to orange;stigmas linear to lanceolate, slightly exceeding bracteoles in mature spikes;pistillate spikes at anthesis cinnamon to light-brown, darkening slightly at maturity;monad pollen;staminate bracteoles (scales) straw to orange-brown colored;mucilage glands present on the adaxial surface of leaf sheathes and adjacent blades. Leaves are 6-18 mm wide, mature pistillate spikes are 13-26 mm wide, and the pistillate and staminate spikes are separated by a gap of 0-8 cm. Some quantitative macroscopic characters including spike width, gap length between pistillate and staminate spikes, and leaf width are useful, but are too variable for conclusive identification, which depends on the above microscopic floral characteristics. Finlayson et al. (1985) combined measurements of the gap between male and female inflorescences with the length and diameter of the female inflorescences to distinguish T. domingensis from T. orientalis in Australia.

Impact

T. domingensis can spread prolifically by rhizomes after seedlings establish in disturbed vegetation, often forming monotypes that reduce wetland plant and animal diversity. The species thrives under eutrophic conditions and artificially stabilized hydroperiods, but in undisturbed, low-nutrient wetlands, T. domingensis often grows sparsely and does not appear to reduce diversity. T. domingensis is economically important in many regions as a weaving material, but when invasive, the species can replace other valuable plant commodities. Short-term Typha control is provided by cutting, burning, or grazing, each followed by flooding, or herbicide, but re-growth from rhizomes and a vast soil seed-bank complicate eradication.

Hosts

T. domingensis can invade the margins of rice fields and lacustrine cornfields (Sykes 1981, cited in Finlayson et al., 1983;Hall, 2008).
Host Plants and Other Plants Affected
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Plant name|Family|Context
Oryza sativa|
Zea mays subsp. mays (sweetcorn)|Poaceae
Biology and Ecology
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Genetics
T. domingensis readily hybridizes with other sympatric species of Typha. T. domingensis x latifolia has mostly abortive pollen and low seed set, while T. angustifolia x domingensis (reported in France and California) is highly fertile and can form hybrid swarms (Geze, 1912, cited in Smith, 1987;Smith, 1967). T. domingensis, T. latifolia, and T. angustifolia share n=15 chromosomes (Smith, 1967). T. domingensis shows ecotypic variation for a number of traits, including salt tolerance, germination temperature, time of flowering, height, rhizome proliferation, and rhizome number (McNaughton, 1966). Because of the worldwide distribution of T. domingensis, quantitative data presented here will likely vary widely among regional ecotypes.
Reproductive Biology
T. domingensis is protogynous, self-compatible, and does not show apomixis (Smith, 1967). Pollen requires strong winds for dispersal, and T. latifolia pollen can travel distances of at least one km (Krattinger, 1975). Despite copious pollen production, self-pollination appears to exceed outcrossing even in dense stands of T. latifolia. Some populations of T. domingensis remain in anthesis for more than a month (McNaughton, 1966). Each inflorescence can produce 600,000 fruits, or 6-17 million seeds per m 2 depending on flowering ramet density, and plants established from seed can flower by the second year (Prunster, 1940, cited in Finlayson et al., 1983;Howard-Williams, 1975). Germination can occur year-round in many climates, given adequate moisture, although germination declines below 20 ° C (Finlayson et al., 1983). In the United States, southern populations germinated at a lower temperature (13 ° C) than their northern counterparts (McNaughton, 1966). Seeds germinate under moist or submerged conditions;in an extreme case, T. domingensis germinated under 80 cm of water and survived for 8 weeks (Nicol and Ganf, 2000). Salinity reduces germination, although limited germination can occur even at 20% salinity (Beare and Zedler, 1987). High salinity prevented T. domingensis from recruiting after a lake drawdown in Malawi (Howard-Williams, 1975). Exposure to light and hypoxia increase germination (Sifton, 1959), which is low under established vegetation (Finlayson et al., 1983). In natural areas not disturbed by humans, disturbance and herbivory by animals could facilitate seedling establishment of Typha seedlings (Svengsouk and Mitsch, 2001).
Lateral rhizomes can facilitate rapid vegetative expansion after seedling establishment. Individual T. latifolia clones can span 60 m (Krattinger, 1983), and T. domingensis can spread laterally at 3-10 m/year (Parsons and Cutherbertson, 1992;Fraga and Kvet, 1993). Rhizome production is stimulated by short days and cold temperatures (McNaughton, 1966).
Physiology and Phenology
In frost-free climates, T. domingensis can produce ramets (culms) year-round, although most emerge in summer and autumn, and do not survive longer than 10 months (Finlayson et al., 1983;Parsons and Cuthbertson, 1992). In a spring-fed wetland in central Mexico, T. domingensis growing in dense stands did not produce new ramets between May and October unless disturbed by leaf harvest (Hall et al., in press). Flowering ramets differentiate by spring, and become fertile by early summer. Grace and Harrison (1986) contend that high rhizome carbohydrate supplies promote Typha ramets to flower rather than to remain vegetative. Repetitive harvesting decreased rhizome starch reserves and flowering ramet density of T. domingensis, but drought stress could promote flowering (Hall, 2008). Carbohydrate dynamics have been studied for T. latifolia. Leaf biomass is at a maximum while rhizome biomass is minimized in late summer. By autumn, leaf carbohydrates have been translocated to rhizomes, biomass increases, and rhizome starch concentrations are maximized (Linde et al., 1976). For T. domingensis in Belize, leaf turnover averages 110 days (Rejmankova et al., 1996). Fraga and Kvet (1993) report that T. domingensis in Cuba had a net primary productivity of 1500 g/m 2 /year. Litterbag experiments showed only 50% decomposition after one year, and organic matter accumulated rapidly.
In flooded conditions, oxygen is conducted to Typha ’s underwater tissues via leaf aerenchyma cells (Sale and Wetzel, 1983), allowing T. domingensis to tolerate water 2 m deep (Finlayson et al., 1983). Flooded seedlings only produced additional ramets, however, when they reached the water surface (Nicol and Ganf 2000). T. domingensis is moderately salt-tolerant, and salinities of up to 5% should not impede vegetative growth or flowering. Salinity 5% prevents growth, and salinity 25% causes leaf mortality, although rhizomes re-sprout if salinity declines (Beare and Zedler, 1987). Freshwater inflows lasting 2 months allowed T. domingensis to invade California salt marshes. T. domingensis thrives in hot climates, and grows well in water at 30 ° C (Finlayson et al., 1983). Parsons and Cuthbertson (1992) reported maximum growth at 32 ° C, declining to 50% at 18 ° C. Typha spp. show a high tolerance for soil and water contaminated by heavy metals (McNaughton et al., 1974).
Nutrition
T. domingensis thrives under high nutrient loads and stable, prolonged, hydroperiods. In the Florida Everglades, T. domingensis invasion correlated with increased phosphorus and water levels, and muck-burning fires (Urban et al., 1993;Newman et al., 1998). Typha ’s limitation by phosphorus is supported by a comparison of soil and plant tissue samples from eutrophic and un-impacted areas of the Everglades (Koch and Reddy, 1992). T. domingensis also appeared limited by phosphorus in wetlands of Mexico’s Yucatan Peninsula and Belize (Rejmankova et al., 1996). In mesocosms, elevated nutrient levels and prolonged hydroperiods increased T. domingensis biomass and tissue phosphorus concentration relative to the co-occurring Cladium jamaicense (Newman et al., 1996). Substantial peat, nitrogen, and phosphorus accumulated where T. domingensis dominated nutrient-rich areas of the Everglades (Craft and Richardson, 1993). Seedlings produced more biomass, had a greater root/shoot ratio, and contained more phosphorous when grown in burned soil than in unburned or surface-burned soil in the Everglades, suggesting that soil-burning fires promote T. domingensis by releasing phosphorus (Smith and Newman, 2001). In low-nutrient areas of the Everglades, Typha is present but does not dominate (Davis, 1994).
Nitrogen and phosphorus appeared to co-limit the congener T. latifolia when it was grown in mesocosms, whereas in the field, T. latifolia increased along a gradient of increasing phosphorus (Svengsouk and Mitsch, 2001). T. x glauca required both nitrogen and phosphorus for growth in a greenhouse experiment, but adding a higher proportion of phosphorus stimulated growth regardless of nutrient concentration (Woo and Zedler, 2002).
Associations
In disturbed and eutrophic wetlands, T. domingensis tends to form monotypes. However, T. x glauca ’s invasive growth may be dependent on anthropogenic modifications (e.g. from dams, wastewater discharge, or irrigation canals). In little-disturbed wetlands where hydroperiods fluctuate seasonally, many genera co-occur with T. domingensis. In Australian wetlands, Baumea, Eleocharis, Gahnia, Melaleuca, Muehlenbeckia, and T. orientalis co-dominate with T. domingensis where water levels fluctuate (Finlayson et al., 1983;Nicol and Ganf, 2000). In Cuba, Bidens, Cyperus, Eleocharis, Hyparrenia, Panicum, and Sagittaria can co-occur with T. domingensis in shallow water, although T. domingensis often forms temporary monotypes in deeper water (Fraga and Kvet 1993). In this system, shrubs can replace Typha because of rapid organic matter accumulation;frequent fire might reduce litter and retard succession. In Africa’s Lake Victoria, T. domingensis is less abundant than the dominant Cyperus or Miscanthidium (Kansiime et al., 2007);in Lake Chad, Vossia, Cyperus, and Phragmites dominate, while T. domingensis is rare (Denny, 1985a). Thompson (1985) ranked T. domingensis as the third most-dominant African wetland plants, behind Phragmites australis and P. mauritianus. In Belize, T. domingensis normally dominates on clay soils with low salinity, while growing sparsely with dominant Eleocharis and Cladium on marl and sandy soil with higher salinity (Rejmankova et al., 1996). T. domingensis monotypes in this region may be relics of phosphorus-rich agricultural run-off. In Iran, T. domingensis and Schoenoplectus tabernaemontani co-dominate diverse wetlands (Karami et al., 2001). In a groundwater-fed wetland in central Mexico, harvesting T. domingensis increased species richness and the recruitment of uncommon species (Hall, 2008). Here, more than 40 species co-occurred with Typha and the co-dominant Schoenoplectus americanus.
Environmental Requirements
T. domingensis tolerates a broad climatic spectrum, growing between 40 ° latitude north and south under a variety of rainfall regimes (Smith, 2000). Although T. domingensis tolerates widely variable hydroperiods, it can decline during extended drawdowns, and grows best under flooded conditions (Rejmankova et al., 1996;Palma-Silva et al., 2005). Rainfall does not appear to limit wide-scale geographic distribution, because even in seasonally dry climates (e.g. central Mexico), T. domingensis can persist in isolated springs or on lakeshores. Seedlings can tolerate anaerobic conditions, but mature plants are intolerant of anaerobic conditions created when leaves are severed below water (Sale and Wetzel, 1983).
Climate
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Climate|Status|Description|Remark
Af - Tropical rainforest climate| Preferred
60mm precipitation per month
Am - Tropical monsoon climate| Preferred
Tropical monsoon climate (60mm precipitation driest month but (100 - [total annual precipitation(mm}/25]))
As - Tropical savanna climate with dry summer| Preferred
60mm precipitation driest month (in summer) and (100 - [total annual precipitation{mm}/25])
Aw - Tropical wet and dry savanna climate| Preferred
60mm precipitation driest month (in winter) and (100 - [total annual precipitation{mm}/25])
BS - Steppe climate| Preferred
430mm and 860mm annual precipitation
BW - Desert climate| Preferred
430mm annual precipitation
C - Temperate/Mesothermal climate| Preferred
Average temp. of coldest month 0°C and 18°C, mean warmest month 10°C
Cf - Warm temperate climate, wet all year| Preferred
Warm average temp. 10°C, Cold average temp. 0°C, wet all year
Cs - Warm temperate climate with dry summer| Preferred
Warm average temp. 10°C, Cold average temp. 0°C, dry summers
Cw - Warm temperate climate with dry winter| Preferred
Warm temperate climate with dry winter (Warm average temp. 10°C, Cold average temp. 0°C, dry winters)
Latitude/Altitude Ranges
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Latitude North (°N)|Latitude South (°S)|Altitude Lower (m)|Altitude Upper (m)
40
40
0
0
Soil Tolerances
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Soil drainage
impeded
seasonally waterlogged
Soil reaction
acid
alkaline
neutral
Soil texture
heavy
light
medium
Special soil tolerances
infertile
other
saline
shallow
sodic
Notes on Natural Enemies
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Herbivory is common but variable. In Australia, kangaroos, rodents, and water birds lightly graze T. domingensis, while water buffalo can cause heavy damage (Finlayson et al., 1983). In Africa, large herbivores do not extensively feed on T. domingensis, despite its abundance (Howard-Williams and Gaudet 1985). In Costa Rica and elsewhere throughout Latin America, cattle heavily graze T. domingensis (McCoy et al., 1994). Muskrats (Ondatra zibethicus) can eliminate entire stands of Typha spp. through herbivory, at least in temperate climates (Kadlec et al., 2007). Barreto et al. (2000) mention a variety of fungal pathogens, although none have been extensively studied in the field. A variety of insects feed on T. latifolia and T. angustifolia. Lepidopteran larvae often inhabit inflorescences, while noctuid caterpillars and coleoptera attack leaves, stalks, and sometimes rhizomes (Grace and Harrison, 1986).
Means of Movement and Dispersal
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Natural Dispersal (Non-Biotic) Typha ’s tiny seeds (1 - 2 mm long) are contained in achenes attached to pistil hairs, and are often dispersed by the wind. Spikes do not shed fruits until they have dried (Krattinger, 1975), often delaying dispersal until many months after seed maturation. The entire female spike sometimes collapses in place, providing a floating platform for germination (Hall, 2008). Masses of achenes and hairs, and rhizomes, can disperse by floating on currents of water (Grace and Harrison 1986;Parsons and Cutherbertson, 1992).
Vector Transmission (Biotic)
When achenes are moistened, seeds are released, which have a pointed end that can become embedded in fish scales (Krattinger, 1975). Also, pistil hairs (with attached acenes) adhere to the clothing of fieldworkers, and could attach to animals as well (S Hall, University of Wisconsin, USA, personal communication, 2008). Mud with embedded seeds readily sticks to humans, livestock, birds, and agricultural implements (Parsons and Cuthbertson, 1992).
Intentional Introduction
Indigenous people in the Northwestern United States propagated T. latifolia using rhizome fragments (Turner and Peacock, 2005). Similar propagation of T. domingensis has not been documented.
Pathway Causes
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Cause|Notes|Long Distance|Local|References
Crop production|Seeds attach to mud on agricultural implements.| Yes
Parsons and Cuthbertson,
1992
Disturbance|Seedlings establish in disturbed vegetation.| Yes
Finlayson et al.,
1983
Hitchhiker|Achenes with hairs attach to humans and animals.| Yes
Yes
Parsons and Cuthbertson,
1992
Interbasin transfers|Achenes and rhizomes disperse with water currents.| Yes
Grace and Harrison,
1986;Parsons and Cuthbertson,
1992
Interconnected waterways|Achenes and rhizomes disperse with water currents.| Yes
Grace and Harrison,
1986;Parsons and Cuthbertson,
1992
Self-propelled|Achenes with hairs are wind-dispersed.| Yes
Krattinger,
1975
Pathway Vectors
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Vector|Notes|Long Distance|Local|References
Clothing, footwear and possessions|Achenes with hairs.| Yes
Parsons and Cuthbertson,
1992
Host and vector organisms|Achenes adhere to fish scales.| Yes
Krattinger,
1975
Water|Achenes with hairs, rhizomes.| Yes
Grace and Harrison,
1986;Parsons and Cuthbertson,
1992
Wind|Achenes with hairs.| Yes
Yes
Krattinger,
1975
Impact Summary
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Category|Impact
Economic/livelihood
Positive and negative
Environment (generally)
Positive and negative
Economic Impact
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T. domingensis can interfere with agriculture in wet areas. With the adoption of year-round rice cropping in Australia, T. domingensis invaded fields and decreased yields by 5% (Sykes 1981, cited in Finlayson et al., 1983). In central Mexico’s Lake Pátzcuaro, T. domingensis can invade low-lying cornfields. This species also tends to replace the bulrush Schoenoplectus californicus, a valuable species traditionally used to weave mats (Hall, 2008). In southern Mexico, T. domingensis invades wetlands used for horse pasture, and replaces valuable fodder (S Hall, University of Wisconsin, USA, personal communication, 2009). In lacustrine wetlands, T. domingensis can interfere with fishing and water transportation (Mitchell, 1985).


Source: cabi.org
Description

B. sylvaticum is a cespitose perennial bunchgrass that is sometimes very weakly rhizomatous. It ranges in height from a few centimeters up to about 200 cm. Sheaths are open and the nodes are typically pubescent. The leaf blades are bright green and remain green throughout the summer, even in dry Mediterranean climates (BA Roy, University of Oregon, USA, personal observation, 2009). The blades are 4-15 mm wide, flat and lax, with variable pubescence. Ligules are variable in size (1-6 mm) and are generally pubescent and ciliate. Plant size and pubescence depend both on habitat (Shouliang and Phillips, 2006) and genotype (Davies and Long, 1991). Racemes are nodding with an average of 9 spikelets, each with 3-24 florets. Lemma awns are 7-15 mm. Excellent full descriptions are published in the Flora of North America (Piep, 2003) and Flora of China (Shouliang and Phillips, 2006), both of which can also be found on line at www.efloras.org/index.aspx.

Recognition

For a grass, B. sylvaticum is relatively easy for botanists to identify because it grows in the shade of the forest (and often along trails, streams and rivers) and is quite pretty: it stays a bright vibrant green all season long, and has broad lax leaves and nodding inflorescences. Nonetheless, for identification it is best to involve a trained botanist as there are a couple of native forest grasses in North America with which it could be confused (for example, Bromus vulgaris, and possibly Melica subulata, Elymus glaucus and Bromus carinatus). Excellent identification information can be found at Piep (2003) and Shouliang and Phillips (2006).

Impact

B. sylvaticum is a bunchgrass naturally occurring in old world temperate forests and temperate zones of tropical Asian mountains. Its extensive native range includes most of Eurasia (e.g. Europe, Russia, China, Japan, India, Indonesia) as well as the Middle East (e.g. Lebanon, Syria, Iran) and North Africa (e.g. Algeria, Eritrea). It is invasive in North America (Piep, 2003), South America (Zuloaga et al., 1994), New Zealand (Edgar and Connor, 2000), and Australia (IBIS, 2009). It is shade tolerant (Murchie and Horton, 1998), spreads rapidly by seeds (Petersen and Philipp, 2001), has a persistent seed bank (Donelan and Thompson, 1980;Buckley et al., 1997) and is long-lived (Haeggström and Skytén, 1996). It forms monocultures and crowds out native plants and rare butterflies (Kaye and Blakeley-Smith, 2006;Severns and Warren, 2008). Furthermore, grasses significantly reduce recruitment of conifers (Powell et al., 1994;Lehmkuhl, 2002;Kruse et al., 2004). It is on noxious weed lists for three USA States: California, Oregon and Washington (CDFA, 2009;NWCB, 2009;ODA, 2009).

Hosts

The Pacific Northwest is world renowned for its timber production from conifers. It has not been established through a controlled study that B. sylvaticum in particular competes with conifers;however, several lines of evidence suggest that this grass will reduce survival and growth of conifer seedlings. First, a number of studies have established that the germination, growth and survival of conifers are negatively affected by competition with grasses (e.g. Powell et al., 1994;Lehmkuhl, 2002;Kruse et al., 2004). Second, at least one timber company (Starker Forests Inc.) has noticed that dense patches of false-brome provide safe cover for voles, which girdle conifer seedlings (G Fitzpatrick, The Nature Conservancy, Oregon, USA, personal communication, 2009). Third, none of the native grasses affected form a solid carpet in the forest, whereas B. sylvaticum does. These dense carpets will compete with seedlings in both logged and unlogged forests, and the build up of thatch may increase fire risk (Anzinger and Radosevich, 2008;False Brome Working Group, 2009). On the other hand, because B. sylvaticum remains green throughout the summer it may decrease fire risk (Anzinger and Radosevich, 2008;False Brome Working Group, 2009). These questions about fire need to be addressed with further research because this grass has the potential to cause ecosystem change if it alters fire behaviour.
The native grasses and herbs that live in the habitats being invaded are likely to diminish in cover and may face local extinction as a result of competition. A recent study showed that under shady high nutrient conditions, B. sylvaticum is a superior competitor to a native prairie grass (Festuca roemeri), a native forest grass (Elymus glaucus) as well as to another aggressive invasive Schedonorus arundinaceus (previously known as Festuca arundinacea) (BA Roy, University of Oregon, USA, personal observation, 2009). Two other grasses that occur sporadically in the forest (Melica subulata and Bromus carinatus) are also quite likely to be negatively affected. In its native range, B. sylvaticum is known for its ability to out compete other species due to its rapid relative growth rate (RGR) and ability to form persistent leaf litter (Grime et al., 1988;Haeggström and Skytén, 1996;Alonso et al., 2001).


Source: cabi.org
Description

Fusarium wilt of bananas is caused by F. oxysporum f.sp. cubense, a common soil inhabitant. Other formae speciales attack a wide variety of other crops, including cotton, flax, tomatoes, cabbages, peas, sweet potatoes, watermelons and oil palms.;The formae speciales of Fusarium oxysporum each produce three types of asexual spores. The macroconidia (22-36 x 4-5 µm, see Wardlaw, 1961 for measurements) are produced most frequently on branched conidiophores in sporodochia on the surface of infected plant parts or in artificial culture. Macroconidia may also be produced singly in the aerial mycelium, especially in culture. The macroconidia are thin-walled with a definite foot cell and a pointed apical cell. Oval or kidney-shaped microconidia (5-7 x 2.5-3 µm) occur on short microconidiophores in the aerial mycelium and are produced in false heads. Both macroconidia and microconidia may also be formed in the xylem vessel elements of infected host plants, but the microconidia are usually more common. The fungus may be spread by macroconidia, microconidia and mycelium within the plant as well as outside the plant. Illustrations of the conidia have been published (Nelson et al., 1983).;Chlamydospores (9 x 7 µm) are thick-walled asexual spores that are usually produced singly in macroconidia or are intercalary or terminal in the hyphae. The contents are highly refractive. Chlamydospores form in dead host-plant tissue in the final stages of wilt development and also in culture. These spores can survive for an extended time in plant debris in soil.;Mutation in culture is a major problem for those working with vascular wilt isolates of F. oxysporum. The sporodochial type often mutates to a 'mycelial' type or to a 'pionnotal' type. The former has abundant aerial mycelium, but few macroconidia, whereas the latter produces little or no aerial mycelium, but abundant macroconidia. These cultures may lose virulence and the ability to produce toxins. Mutants occur more frequently if the fungus is grown on a medium that is rich in carbohydrates.

Symptons

Banana;The various symptoms of Fusarium wilt on banana are described and well illustrated by Ploetz and Pegg (1999).;The first external symptoms of Fusarium wilt on bananas is a faint off-green to pale-yellow streak or patch at the base of the petiole of one of the two oldest leaves. The disease can then progress in different ways. The older leaves can yellow, beginning with patches at the leaf margin. Yellowing progresses from the older to the younger leaves until only the recently unfurled or partially unfurled centre leaf remains erect and green. This process may take from 1 to 3 weeks in cultivar 'Gros Michel'. Often the yellow leaves remain erect for 1-2 weeks or some may collapse at the petiole and hang down the pseudostem. In contrast to this 'yellow syndrome', leaves may remain completely green except for a petiole streak or patch but collapse as a result of buckling of the petiole. The leaves fall, the oldest first, until they hang about the plant like a skirt. Eventually, all leaves on infected plants fall down and dry up. The youngest are the last to fall and often stand unusually erect.;Splitting of the base of the pseudostem is another symptom as is necrosis of the emerging heart leaf. Other symptoms include irregular, pale margins on new leaves and the wrinkling and distortion of the lamina. Internodes may also shorten (Stover, 1962, 1972, Jones, 1994, Moore et al., 1995).;The characteristic internal symptom of Fusarium wilt is vascular discoloration. This varies from one or two strands in the oldest and outermost pseudostem leaf sheaths in the early stages of disease to heavy discoloration throughout the pseudostem and fruit stalk in the later disease stages. Discoloration varies from pale yellow in the early stages to dark red or almost black in later stages. The discoloration is most pronounced in the rhizome in the area of dense vascularization where the stele joins the cortex. When symptoms first appear, a small or large portion of the rhizome may be infected. Eventually, almost the entire differentiated vascular system is invaded. The infection may or may not pass into young budding suckers or mature 'daughter' suckers. Where it does, discoloration of vascular strands may be visible in the excised sucker. Usually, suckers less than 1.5 m tall and ca. 4 months old do not show external symptoms. Where wilt is epidemic and spreading rapidly, suckers are usually infected and seldom grow to produce fruit. Above- and below-ground parts of affected plants eventually rot and die.;Fusarium wilt was reported to occur on banana cultivars of the 'Mutika-Lujugira' (AAA genome) subgroup in East Africa above 1400 m. Internal symptoms were much less extensive than those described above and external symptoms more subtle, comprising thin pseudostems and small fingers. Nevertheless, symptomatic plants were recognized by smallholders and were rogued. These mild symptoms were initially believed to be indicative of an attack on a plant whose defences have been weakened as a result of cooler conditions or other predisposing factors at altitude (Ploetz et al., 1994). Given the importance of this banana group, also referred to locally as ÔEast African highland bananasÕ, to local trade and as a staple food, further investigation was merited. This revealed that the disorder also affected non-indigenous banana types, including Cavendish and Bluggoe (which were not affected by Fusarium wilt) and was related to abnormal soil nutrient levels and farm management practice. Discoloration similar to that caused by F. oxysporum f.sp. cubense was observed in vascular tissues of affected plants. Fusarium pallidoroseum (syn. Fusarium semitectum) was consistently isolated from such tissues but found to be non-pathogenic. F. oxysporum was not recovered (Kangire and Rutherford, 2001, Rutherford, 2006).

Hosts

F. oxysporum f.sp. cubense is one of around 100 formae speciales (special forms) of F. oxysporum which cause vascular wilts of flowering plants (Gerlach and Nirenberg, 1982). Hosts of the various formae speciales are usually restricted to a limited and related set of taxa. As currently defined, F. oxysporum f.sp. cubense affects the following species in the order Zingiberales: in the family Musaceae, Musa acuminata, M. balbisiana, M. schizocarpa and M. textilis, and in the family Heliconeaceae, Heliconia caribaea, H. chartacea, H. crassa, H. collinsiana, H. latispatha, H. mariae, H. rostrata and H. vellerigera (Stover, 1962, Waite, 1963). Additional hosts include hybrids between M. acuminata and M. balbisiana, and M. acuminata and M. schizocarpa.;F. oxysporum f.sp. cubense may survive as a parasite of non-host weed species. Three species of grass (Paspalum fasciculatum, Panicum purpurascens [ Brachiaria mutica ] and Ixophorus unisetus) and Commelina diffusa have been implicated (Waite and Dunlap, 1953).


Source: cabi.org
Description

Adult Papuana huebneri are black, shiny and 15-20 mm long. The size and number of head horns in taro beetles varies between species and sexes;P. huebneri has only one small horn, which is larger in the male than the female (Macfarlane, 1987a).

Recognition

Taro beetles can be detected by: (1) digging up wilting taro plants and examining them for signs of damage;(2) using light traps, particularly on moonless and rainy nights;and (3) sampling wild plant species (e.g. banana, sugarcane and grasses such as Paspalum spp. and Brachiaria mutica) at breeding sites, especially along river banks, on rotting logs and in compost heaps (Carmichael et al., 2008;Tsatsia and Jackson, 2014;TaroPest, 2015).

Symptons

Adult taro beetles burrow into the soft trunks, plant bases and corms of a range of plants, including taro, making large holes or cavities up to 2 cm in diameter (McGlashan, 2006). The feeding tunnels and associated frass may be visible in infested corms (Biosecurity Australia, 2011). The amount of damage to the crop depends on the age of the plants when attacked and the density of infestation. Feeding activity can cause wilting and even the death of affected plants, particularly in young plants if the beetles bore into the growing points. Older plants infested by beetles grow slowly and a few or all of the leaves wilt (TaroPest, 2015). In severely damaged plants tunnels may run together to form large cavities, making the damaged corms more susceptible to fungal infections (Macfarlane, 1987a;Onwueme, 1999). Similar symptoms of damage are caused to other root crops, e.g. sweet potato, yams and potato (McGlashan, 2006). Taro beetles can ring-bark young tea, cocoa and coffee plants in the field and bore into seedlings of oil palm and cocoa (Aloalii et al., 1993).

Impact

Papuana huebneri is one of at least 19 species of known taro beetles native to the Indo-Pacific region;it is native to Papua New Guinea, the Molucca Islands in Indonesia, the Solomon Islands and Vanuatu, and has been introduced to Kiribati. Taro (Colocasia esculenta) is an important crop in these countries;high infestations of P. huebneri can completely destroy taro corms, and low infestations can reduce their marketability. The beetle also attacks swamp taro or babai (Cyrtosperma chamissonis [ Cyrtosperma merkusii ]), which is grown for consumption on ceremonial occasions. Infestations of taro beetles, including P. huebneri, have led to the abandonment of taro and swamp taro pits in the Solomon Islands and Kiribati, resulting in the loss of genetic diversity of these crops and undermining cultural traditions. P. huebneri also attacks a variety of other plants, although usually less seriously. Management today relies on an integrated pest management strategy, combining cultural control measures with the use of insecticides and the fungal pathogen Metarhizium anisopliae.

Hosts

Papuana huebneri is a pest of taro (Colocasia esculenta;known as ‘dalo’ in Fijian;McGlashan, 2006) (Masamdu, 2001;International Business Publications, 2010), which is grown primarily as a subsistence crop in many Pacific Island countries, including Kiribati, Papua New Guinea, the Solomon Islands and Vanuatu, where P. huebneri is found (Aloalii et al., 1993). Taro also has value in gift-giving and ceremonial activities (Braidotti, 2006;Lal, 2008). The beetle also attacks swamp taro or babai (Cyrtosperma merkusii or Cyrtosperma chamissonis), which is grown for consumption on ceremonial occasions (Food and Agriculture Organization, 1974;Dharmaraju, 1982;International Business Publications, 2010).
Other plants attacked by Papuana huebneri include tannia (Xanthosoma sagittifolium), bananas (Musa spp.), Canna lily (Canna indica), pandanus (Pandanus odoratissimus [ Pandanus utilis or P. odorifer ]), the bark of tea (Camellia sinensis), coffee (Coffea spp.) and cocoa (Theobroma cacao), the fern Angiopteris evecta (Masamdu, 2001), and occasionally the Chinese cabbage Brassica chinensis [ Brassica rapa ] (International Business Publications, 2010).
Species of Papuana behave similarly to each other and feed on the same host plants (TaroPest, 2015). For taro beetles in general, primary host plants other than taro include giant taro (Alocasia macrorrhizzos), Amorphophallus spp., the fern Angiopteris evecta, banana (Musa spp.) and tannia (Xanthosoma sagittifolium). Secondary hosts include pineapple (Ananas comosus), groundnut (Arachis hypogaea), betel nut (Areca catechu), cabbage (Brassica oleracea), canna lily (Canna indica), coconut (Cocos nucifera), Commelina spp., Crinum spp., yam (Dioscorea spp.), oil palm (Elaeis guineensis), sweet potato (Ipomoea batatas), Marattia spp., pandanus (Pandanus odoratissimus [ Pandanus utilis or P. odorifer ]), Saccharum spp. including sugarcane (Saccharum officinarum) and Saccharum edule [ Saccharum spontaneum var. edulis ], and potato (Solanum tuberosum);they occasionally ring bark young tea (Camellia sinensis), coffee (Coffea spp.) and cocoa (Theobroma cacao) plants (Macfarlane, 1987b;Aloalii et al., 1993;Masamdu and Simbiken, 2001;Masamdu, 2001;Tsatsia and Jackson, 2014;TaroPest, 2015).


Source: cabi.org
Host plants Myzus persicae
Description


Adult wingless parthenogenetic females are oval-bodied, 1.2-2.1 mm in body length, of very variable colour;whitish green, pale yellow green, grey green, mid-green, dark green, pink or red. The tobacco form (nicotianae) varies even more and can also be bright yellow, or almost black. Apart from genetically determined colour variation, any one genotype will be more deeply pigmented green or magenta in cold conditions. Immature stages are quite shiny, but adults are less so. Winged morphs have a black central dorsal patch on the abdomen. Immatures of the winged females are often pink or red, especially in autumn populations, and immature males are yellowish (Blackman and Eastop, 1985).
Distinguishing characters of the M. persicae group with a hand lens or under the microscope are the convergent inner faces of the antennal tubercles in dorsal view, and the very slightly clavate siphunculi, which are usually dark-tipped and about as long as the terminal process of the antenna.
M. persicae alate virginoparae from populations derived from overwintering eggs on Prunus have cylindrical cornicles, whereas those from populations derived from overwintering virginoparae are clavate.

Recognition


On Prunus persica, inspect for curled leaves, in which colonies develop in early spring.
Monitoring is important in field crops, but M. persicae transmits viruses of crops such as sugar beet and potato at low densities, and is therefore difficult to detect on the crop before the damage is done. Suction and yellow traps are the most efficient way to detect first migration of winged aphids into the crop. Networks of suction traps have been developed to monitor migrating aphids, for example, the Rothamsted Insect Survey in the UK and AGRAPHID in France (Hulle et al., 1987), as part of the 'Euraphid' forecasting system in European Union countries. Much effort has been expended on developing forecasting methods, for example for sugarbeet (Harrington et al., 1989). Appropriate applications of insecticides are often based on monitoring data. Insecticide application in sugar beet against M. persicae is only necessary when aphids are carrying yellows viruses. Vertical nets placed downwind of fields of infected potato plants can be used to quantify the proportion of M. persicae carrying virus (diagnosed by use of ELISA;see Diagnosis).

Symptons


Effect of infestation depends greatly on host plant and transmitted viruses. Spring populations on peach cause severe leaf curl and shoot distortion. In potato, PLRV symptoms are leaf rolling and tuber stem necrosis. In sugarbeet, beet yellows viruses (BYV, BYDV, BWYV) cause yellowing in older leaves, chlorotic spotting, and thickening of the leaves, which become leathery and brittle.
On many crop plants (for example, potato, brassicas, sugarbeet) M. persicae only occurs at low densities, particularly on older leaves. Large colonies of the tobacco form (nicotianae) occur on growing stems and younger leaves.

Hosts


The winter (primary) host of M. persicae is almost invariably Prunus persica (peach), including var. nectarina;sometimes P. nigra in USA, and possibly P. tenella, P. nana, P. serotina, P. americana and peach-almond hybrids. It is not clear whether the sexual part of the life-cycle is completed on species other than P. persica and P. nigra.
M. persicae is highly polyphagous on summer hosts, which are in over 40 different families, including Brassicaceae, Solanaceae, Poaceae, Leguminosae, Cyperaceae, Convolvulaceae, Chenopodiaceae, Compositae, Cucurbitaceae and Umbelliferae. Summer hosts include many economically important plants.


Source: cabi.org
Host plants Myzus cerasi
Title: Myzus cerasi
Description

M. cerasi is a small to medium-sized aphid. Adults are shiny, very dark brown to black, with a sclerotized dorsum. Siphunculi and cauda are entirely black. The legs and antennae are yellow and black.
Fundatrices differ from apterous summer virginoparae in having relatively shorter antennae (0.75-1.15 cf. 1.25-1.60 mm) and hind tibiae (0.60-0.70 mm);otherwise similar (Palmer, 1952).
Apterous summer virginoparae have a shiny black body, siphunculi and antennae. Cauda dusky to black, and tibiae yellow except tips. The siphunculi are somewhat broader at the base, constricted just before definite flange, curved outwards, and, when at rest, are held against the body so that the tips converge and nearly touch. Cauda is rather broad at base and strongly tapered, bearing 2-3 lateral pairs of hairs (Palmer, 1952). Apterae on secondary host-plants can sometimes vary in colour from dark brown to olive-green or yellowish-brown. Apterae body lengths in range 1.5-2.6 mm (Blackman and Eastop, 1984).
Alate virginoparae have a yellow-brown abdomen, with a large black central dorsal patch. Colours otherwise as apterous virginoparae. Siphunculi cylindrical, less tapered and curved than in apterous virginoparae. Cauda tapered to nearly cylindrical and bearing 2-3 pairs of lateral hairs. Alatae body length in range 1.4-2.1 mm (Palmer, 1952;Blackman and Eastop, 1984).
Oviparae are apterous. Body length around 1.10 mm. Hind tibiae with proximal half slightly swollen (Palmer, 1952).
Males are alate. Deep black, with all appendages black except yellow tibiae. Body length around 1.30 mm (Palmer, 1952).
Morphology varies, however, with geographic region. Aphids collected in India differed from those collected in Japan and elsewhere in not having entirely black siphunculi and cauda, and differed from those collected in Australia by having paler dorsum and shorter processus terminalis (Raychaudhuri, 1980).
Diploid chromosome number is 2n=10 (Blackman and Eastop, 1984). Some Indian populations have been reported as having 2n=12;these are probably the subspecies M. cerasi umefoliae (Blackman and Eastop, 1994).

Recognition


Colonies can be found via inspection of curled young growing shoots of cherry trees in the spring. Winged M. cerasi in cherry orchards later in the spring and early summer can be detected using yellow sticky traps.

Symptons


Colonies of M. cerasi form dense colonies at the growing apices of cherry trees in spring. Initial damage is due to leaf curling. Continual feeding causes deformation of shoot growth and can also lead to the formation of pseudogalls (open galls). Galling is thought to be due to the action of aphid saliva, which contains a physiologically-active substance (alpha-glucosidase) known to influence plant growth.

Hosts


Primary host plants are Prunus cerasus (Morello cherry) and Prunus avium (sweet cherry), and sometimes other Prunus species (Rosaceae). Secondary hosts occur in the Rubiaceae (Galium spp.), Scrophulariaceae (Veronica spp.) and Cruciferae (Capsella spp.), and occasionally Caprifoliaceae and Compositae. Different secondary hosts are utilized in different geographical regions, for example, cruciferous hosts are important in the USA (Gilmore, 1960;Blackman and Eastop, 1984).


Source: cabi.org
Title: Myzus cerasi
Host plants Drosophila suzukii
Description

D. suzukii adults are 2-3 mm long with red eyes, a pale brown or yellowish brown thorax and black transverse stripes on the abdomen. The antennae are short and stubby with branched arista. Sexual dimorphism is evident: males display a dark spot on the leading top edge of each wing and females are larger than males and possess a large serrated ovipositor.

Recognition


Detailed morphological description of each stage is given by Kanzawa (1935). A more recently updated description, including references for additional morphological details, is given by Hauser (2011), and another by Vlach (2010), who published a dichotomous key for easy identification. An easy-to-use description of the combination of diagnostic characters that could be used for tentative identification of D. suzukii within its subgroup is given by both Hauser (2011) and Cini et al. (2012). Fruit infestation symptoms are described by Walton et al. (2010).
The dark spots on the male wings together with two sets of black tarsal combs make the identification of the males relatively easy, although the males of some other species do also have wing spots. The wing spots of D. subpulchrella are particularly similar in shape and position to those of D. suzukii. Males without dark wing spots can occur, as it takes two full days before the spots become obvious, although they start to appear within 10 hours of emergence at high temperatures.
The situation is complex for the eggs, larvae and pupae, as no reliable morphological diagnostic features have been identified (Okada, 1968). The eggs of D. suzukii have two respiratory appendages but this character is not species-specific. Instar stages can be estimated by the size of larvae and the colour of the mouthparts, but it is most accurately judged by pre-respiratory ducts (Kanzawa, 1935;Walsh et al., 2011).
Larvae are often undetected inside the fruit. The infested fruits can be detected only by visual inspection under optical magnification (15-20 x magnification). Detection of larvae inside the fruits can also be performed by immersion of fruit samples in sugar or salt solution. Sugar solution can be prepared using approximately 1 part sugar to 6 parts water in order to reach at least 15°Brix. Gently crush the fruits and wait for 10 minutes until the larvae in the sample float to the surface. The same procedure can also be followed using a salt solution, adding 1 part salt to 16 parts water (BCMA, 2013).
Traps baited with different baits have been proposed for detecting adults in the field. Traps can be installed around a site where fruits for shipment are stored, and for early detection in potentially newly-invaded areas, such as near fruit markets, warehouses of food retailers and sites where rotten fruits are disposed. For more information on traps and baits, see the Monitoring and Surveillance section in Prevention and Control.

Symptons

D. suzukii larvae cause damage by feeding on the pulp inside fruit and berries. The infested fruit begins to collapse around the feeding site causing a depression or visible blemish on the fruit. The oviposition scar exposes the fruit to secondary attack by pathogens and other insects, which may cause rotting (Hauser et al., 2009;Walton et al., 2010).

Impact


The fruit fly D. suzukii is a fruit crop pest and is a serious economic threat to soft summer fruit. A polyphagous pest, it infests a wide range of fruit crops, included grape, as well as an increasing number of wild fruits. D. suzukii is an economically damaging pest because the females are able to infest thin-skinned fruits before harvest and the larvae destroy the fruit pulp by feeding. The species is endemic in Asia. It was first recorded as invasive in Hawaii in 1980 and then simultaneously in California and in Europe in 2008. Since 2008 it has spread rapidly throughout the temperate regions of North America and Europe, due to global trade and the initial lack of regulation over the spread of any Drosophila. This species has a high reproductive rate and short generation time;D. suzukii can theoretically have up to 13 generations per year, which may contribute towards rapid spread, given available suitable hosts. D. suzukii is listed on the EPPO alert list.

Hosts

D. suzukii is predisposed towards infesting and developing in undamaged, ripening fruit. Fruits become susceptible to D. suzukii as they start to change colour, which coincides with softening skins and higher sugar levels (Burrack et al., 2013). There are differences in fruit susceptibility within species and among varieties within the same fruit species (Lee et al., 2011). Fruit penetration force is one potential measure of host susceptibility, but host attractiveness will likely depend upon additional factors, such as soluble sugar content (Burrack et al., 2013). If there is no suitable fruit available, then D. suzukii will attack damaged or deteriorating fruit (Kanzawa, 1935;Lee et al., 2011). Non-commercially marketed fallen fruit or damaged fruit of the following plant hosts may also be attacked: Prunus persica, Malus pumila var. domestica, Prunus triflora, Prunus armeniaca, Pyrus pyrifolia, Pyrus sinensis, Eriobotrya japonica, Lycopersicum esculentum (Kanzawa, 1939) and Rubus microphyllus (Mitsui et al., 2010), as well as over-ripped figs still on the tree (Ficus carica) (Yu et al., 2013).
D. suzukii has been reared from rotting strawberry guava fruits (Psidium cattleianum) collected from trees and on the ground (Kido et al., 1996). It has been observed feeding upon injured or culled fruit including apple and oranges (Walsh et al., 2001).
A recently extensive study on seasonal life cycles and food resources of D. suzukii from low to high altitudes in central Japan (Mitsui et al., 2010) confirmed that D. suzukii emerges almost only from fruits. Some D. suzukii individuals emerged from the fruits of Rubus crataegifolius, Alangium platanifolium, Cornus kousa, Torreya nucifera and Viburnum dilatatum. Grassi et al. (2011) reared D. suzukii also on Prunus laurocerasus and Mann and Stelinski (2011) reported Ribes spp. as host plant of D. suzukii, but this latest observation has not been confirmed in Europe. D. suzukii adults also emerged from the flowers of Styrax japonicus (Mitsui et al., 2010), and in early spring in southern Japan it was also observed to breed on the flowers of Camellia japonica (Nishiharu, 1980).
This field of work is not well described, and so the list of Host Plants and Other Plants Affected contains probable as well as reported hosts.

Biological Control
Early experiments tested the efficacy of Phaenopria spp. (Hymenoptera: Diapriidae) under laboratory conditions, but results were unsatisfactory (Kanzawa, 1939).<br>Studies to determine the current presence of indigenous parasitoid biological control agents and their efficacy in controlling D. suzukii were undertaken both in North America and in Europe by different research groups (Brown et al., 2011;Chabert et al., 2012;Rossi Stacconi et al., 2013). Under laboratory conditions several naturally occurring parasitoids of drosophilids in France were able to successfully parasitize D.suzukii. These included two larval parasitoids, Leptopilina heterotoma and Leptopilina boulardi, and two pupal parasitoids, Pachycrepoideus vindemiae (Hymenoptera: Pteromalidae) and Trichopria drosophilae (Hymenoptera: Diapriidae). Both Leptopilina parasitoids displayed high parasitism rates on D. suzukii, but because of the strong immune response of the host larvae, they did not give rise to an adult wasp (Chabert et al., 2012).<br>D. suzukii produces up to five times more hemocytes than D. melanogaster, making it significantly more resistant to wasp parasitism (Kacsoh and Schlenke, 2012) and making it less likely for indigenous specialized parasitoids to shift host onto it. While parasitization by L. heterotoma induced a decrease in the number of circulating haemocytes in D. melanogaster, it led to a large increase in the total haemocyte counts of D. suzukii (Poyet et al., 2013).<br>The observed difference between the immune response towards L. heterotoma in D. suzukii and D. melanogaster could suggest that European populations of L. heterotoma are not adapted to this new exotic host (Poyet et al., 2013);however, this hypothesis disagrees with the recent observations of a European-wide strain of L. heterotoma that is able to develop and emerge from D. suzukii. (Rossi Stacconi et al., 2013). It is probable that the European-wide strain of L. heterotoma has more effective venom, or that the strain of L. heterotoma used in the original study had lost its ability to develop on D. suzukii because of continued laboratory rearing on D. melanogaster.<br>Pupal parasitoids seem less susceptible to the high hemocyte levels of D. suzukii and they appear to have the highest potential for use in biocontrol of D. suzukii (Kacsoh and Schlenke, 2012). This was confirmed by the successful parasitism rate obtained with a pupal parasitoid by Chabert et al. (2012).<br>The pupal ectoparassitoid P. vindemiae has also been found in association with D. suzukii in orchards and vineyards, both in USA and in Europe (Brown et al., 2011;Rossi Stacconi et al. 2013).<br>Predators of D. suzukii include several species of the bug genus Orius, a generalist predator, which were observed feeding on D. suzukii larvae in backyard raspberries in the autumn of 2009 (Walsh et al., 2011). Preliminary laboratory studies with O. insidiosus (Walsh et al., 2011), O. laevigatus and O. maiusculus (V. Malagnini, personal comm.) indicated that they can feed on D. suzukii larvae infesting blueberries, but their effective control of the pest population have not been proved yet.<br>The activity of microorganisms, as well as the intimate association of the pest species with endosymbionts, has not yet been exploited for biocontrol purpose.<br>Recently, DNA viruses have been isolated in Drosophila species (Unkless, 2011) and were found to be related to other viruses used for pest control.<br>Strains of endosymbiotic bacterium Wolbachia associated with D. suzukii populations have been collected in both the USA and Italy (Siozios et al., 2013;Tochen et al., 2014). These findings suggest the possibility of control of D. suzukii based on pathogens.

Source: cabi.org
Host plants Ferrisia virgata
Description


In life, adult females are oval, up to 5 mm long, greyish-yellow, with two longitudinal, submedian, interrupted dark stripes on the dorsum showing through the waxy secretion -- hence the common name 'striped mealybug'. The dorsum also bears numerous straight, glassy threads of wax up to 4.0-4.5 mm long. Several members of the genus Ferrisia have this appearance in life, so authoritative identification requires expert study of stained, slide-mounted adult females using the key in Kaydan and Gullan (2012), or nucleotide sequence data.
Slide-mounted adult female Ferrisia species are easy to recognise by the presence of only one pair of cerarii, situated on the anal lobes, and the presence of enlarged tubular ducts, each with the orifice surrounded by a flat, circular, sclerotized area associated with one or more short setae. Kaydan and Gullan (2012) provided a thorough revision of the genus Ferrisia and a morphological key to world species, including detailed morphological description, illustration and discussion of F. virgata. F. virgata is very difficult to separate from some of the other species, particularly F. dasylirii. It has both anterior and posterior pairs of ostioles;ventral oral-collar tubular ducts of at least 2 sizes;smaller ducts present singly or in segmental clusters on body margin, only on last 2–3 abdominal segments;minute discoidal pores in sclerotised area of enlarged dorsal tubular ducts and larger ventral oral-collar tubular ducts rarely if ever touching rim of duct opening (or only very rarely on ventral ducts);discoidal pores associated with sclerotised area around orifices of dorsal enlarged tubular ducts on anterior abdomen normally not touching outer margin of sclerotised area and very rarely projecting from that margin;dorsal enlarged tubular ducts numbering 69-101;abdominal segment VI with 11-28 multilocular disc pores, usually with more than 15 in a double row;each anal lobe cerarius with 3 (occasionally 2) enlarged conical setae;and hind coxa with translucent pores (Kaydan and Gullan, 2012).

Recognition


Heavy infestations are conspicuous because of the white waxy secretions, white masses of male tests (waxy filamentous cocoons) and sooty moulds growing on the excreted honeydew. Colonies often occur at the growing points, around the stem nodes, on the undersides of leaves and on the fruit.

Symptons


Infestations of F. virgata remain clustered around the terminal shoots, leaves and fruit, sucking plant sap which results in yellowing, withering and drying of plants and premature shedding of leaves and fruit. The mealybugs do not feed on phloem very often, so unlike many mealybug species they do not produce huge quantities of sugary honeydew. What honeydew is produced can foul foliage and fruit and serve as a medium for the growth of black sooty moulds. Sooty moulds and wax deposits can block light and air from the plant, sometimes reducing photosynthesis and hence plant vigour and crop yield.

Impact

Ferrisia virgata is a highly polyphagous mealybug. It reproduces quite rapidly in tropical conditions, but it tolerates subtropical and to some extent temperate conditions too. It has been reported on host-plants belonging to over 203 genera in 77 families, and can damage many crops, particularly tropical fruit, nut and spice crops and field crops like soybean and tomato. It is known to transmit plant badnavirus diseases of cocoa and black pepper. It is of Neotropical origin and spread around the world in only about 10 years after being first described from Jamaica. Its polyphagy has facilitated its spread by human transport of infested plants, and it is now established in all the subtropical and tropical zoogeographic regions. Its small size and cryptic habits make it difficult to detect and identify at plant quarantine inspection. The increase in international trade in fresh plant material in recent years is likely to facilitate its continued spread.

Hosts

F. virgata is one of the most highly polyphagous mealybugs known, attacking plant species belonging to some 203 genera in 77 families (García et al., 2016). Many of the host species belong to the Fabaceae and Euphorbiaceae. Among the hosts of economic importance are avocado, banana, betel vine, black pepper, cassava, cashew, cauliflower, citrus, cocoa, coffee, cotton, custard apple, aunergine, grapevine, guava, jute, lantana, Leucaena, litchi, mango, oil palm, pigeon pea, pineapple, soyabean and tomato. Acalypha species are apparently a favoured host-plant in many places (Kaydan and Gullan, 2012).


Source: cabi.org
Description

Matthias et al. (2008) should be consulted for a description of P. dominula, but the following provides an introduction and is mainly based on this publication, unless otherwise stated

Recognition

Wegner and Jordan (2005) assessed three liquid lures for trapping social wasps, including P. dominula. They compared two citrus-based sodas and an isobutanol-acetic acid mixture, and reported that Polistes and Dolichovespula were found in significantly lower numbers than Vespula. However, they concluded that the citrus products were better than the known wasp attractant for attracting almost all of the wasp species.
In an earlier study by Landolt et al. (1999) in the USA, it was shown that the attractant properties of an isobutanol-acetic acid mixture varied according to location. Females of P. dominula were attracted to the mixture in Oklahoma.

Impact

P. dominula is a primitively eusocial paper wasp native to Mediterranean Europe. It is introduced and invasive in North America (Weiner et al., 2012). It is also naturalized in the Western Cape Province of South Africa (Veldtman et al., 2012).


Source: cabi.org
Description

V. velutina is highly variable in colour and 10 subspecies have been identified (https://www.cabi.org/ISC/datasheet/109164#232C47A5-7C02-427F-82E5-D5A688..." Vecht 1957;https://www.cabi.org/ISC/datasheet/109164#2C0D6014-E428-464E-A3BD-5BEF21..." Carpenter and Kojima 1997;https://www.cabi.org/ISC/datasheet/109164#01E52E03-1E70-4BB4-B22D-0D07CD..." Nguyen et al., 2006). The subspecies nigrithorax du Buysson (1905) is invasive in Europe, where it varies in size from 17 to 32 mm (Rome and Villemant, 2018).

Impact

Vespa velutina (Hymenoptera: Vespidae) is a hornet of Asian origin which is a generalist predator of medium- to large-sized insects, and scavenger of vertebrate carrion. It has large impacts on Diptera and social hymenopterans, and in particular on honey bees (Apis spp.). It has recently been spreading in Asia (it is an invasive species in South Korea and Japan), and the subspecies V. v. nigrithorax has been accidentally introduced to Europe where it was first recorded from southern France in 2005. Since then it has been found in Spain, Portugal, Belgium, Italy, the UK, the Netherlands, Germany, the Channel Islands and the Balearic Islands. This invasive species threatens honey production and native pollinating insects. It may be introduced and transported accidentally with soil associated with plants, garden furniture and pots, timber, vegetables, camping equipment, etc.


Source: cabi.org
Description


Annual or short-term perennial, stems 10-60(-120) cm, mostly procumbent. Leaves cauline. Leaves rhombic-ovate to triangular, 1.5-3.5 cm long, 1-3 cm wide, with conspicuous glands on both surfaces, margins irregularly serrate above the middle, base cuneate, petioles 0.3-1.5 cm long. Heads 4-6 mm in diameter, generally solitary, with 3-8 white-cream-yellow ray florets and 3-8 yellowish disc florets functionally staminate. The single-seeded fruits (cypselae) are each enclosed within and shed with an often hardened, ± prickly perigynium, ultimately plumply ellipsoid to fusiform, or ± compressed (PIER, 2015;PROTA, 2015;ZipcodeZoo, 2015).

Impact

Acanthospermum australe is a creeping annual or short-lived perennial plant, which originates from the tropics and sub-tropics of Central and South America. A. australe has been introduced to China, Australia, Africa, and the USA, where it is classed as invasive in the states of Hawaii and Oregon. It spreads to form dense mats that can smother other low-growing vegetation. In Australia, A. australe is seen as a threat to native mat-forming species in coastal sand dunes and in hind-dune vegetation. It is also regarded as an invasive species within its native range in Brazil, where it occurs in conservation areas.


Source: cabi.org
Description


The following description is taken from Flora of Pakistan (2015).

Impact

A. ochroleuca is an annual herb native to Central America. It has been introduced into Australia, Africa, tropical Asia, New Zealand and a number of oceanic islands where it has become invasive. It is most common in disturbed areas such as roadsides, mining dumps, rabbit warrens, recently cultivated paddocks, degraded land and over-grazed pastures. This species produces a large number of seed which can be accidentally introduced into new areas as a seed contaminant. It is often a problem in agricultural land but also has the potential to outcompete native species and decrease biodiversity. A. ochroleuca is toxic to humans and livestock and has thorny spines which can cause injury.


Source: cabi.org
Description


Eggs

Recognition


The majority of thrips species are so small and cryptic that, except when present in very large numbers, many inspectors and commercial operators may fail to see them. Adults and larvae are able to hide in concealed places on plants such as beneath plant hairs, within tight buds, enclosed in developing leaves, or underneath the calyx of fruits. Eggs are laid concealed within plant tissues. Casual inspection may thus not reveal the presence of thrips, and even insecticide treatment may be ineffective because the chemical fails to contact the hidden thrips. Effective detection methods have yet to be deployed by most quarantine inspection systems, reliance usually being placed on inspection for feeding damage and simple beating to reveal thrips. However, adult and larval thrips can be extracted from plant material within two or three minutes if a sample is placed in a small Tullgren Funnel using turpentine as an irritant rather than light;the living thrips then run down into a glass tube at the bottom of the funnel where they are readily observed and counted.
Infestation levels in glasshouse crops are usually monitored by means of blue or yellow sticky traps. One shade of blue is particularly attractive to flying adult thrips and is widely used for monitoring the species (Brødsgaard, 1989a). Pheromone lures that attract males and females are now available to increase the sensitivity of monitoring at low levels of infestation or in easily damaged crops (Hamilton et al., 2005). Thrips can also be monitored by extracting thrips from flowers and recording their numbers or the percentage occupancy of flowers (Navas et al., 1994;Steiner and Goodwin, 2005). Western flower thrips adults are easily carried into glasshouses by wind, as well as on the clothes or in the hair of working personnel, thus making re-infestation from surrounding weeds a constant probability. Indeed, weed control around a crop, whether inside a glasshouse or on surrounding land, is the first measure to be adopted in any control strategy. Thrips are also easily carried on equipment and containers that have not been properly cleaned, and infestations in sterile laboratories with filtered air are usually due to thrips being carried in on the clothes and hair of workers. Nationally and internationally, F. occidentalis is readily transported to new areas on all types of planting material as well as on cut flowers, both commercial and domestic (Vierbergen, 1995).

Symptons


The symptoms of infestation by F. occidentalis vary widely among the different plants that are attacked. On roses or gerberas with red flowers, or on dark Saintpaulia flowers, feeding damage is readily visible as white streaking. This type of damage is less apparent on white or yellow flowers, and these commonly tolerate very much higher thrips populations with no visible symptoms. Severe infestation leads to deformation of buds if the feeding occurs before these start opening. Capsicums and cucumbers that have been attacked whilst young, show serious distortions as they mature. Leaf damage is variable, but includes silvering due to necrotic plant cells that have been drained of their contents by thrips feeding, malformation due to uneven growth, and a range of spots and other feeding scars. Eggs laid in petal tissue cause a 'pimpling' effect in flowers such as orchids. Egg laying on sensitive fruits such as table grapes, tomatoes and apples leads to the spotting of the skin of the fruit, which reduces the aesthetic value of the fruit. It can also lead to splitting and subsequent entry of fungi. However, the most serious effect of thrips feeding is due to the transmission of tospoviruses into susceptible crops, such as tomatoes, capsicums, lettuce or Impatiens. At least five different tospoviruses are known to be transmitted by western flower thrips and more may well be discovered: Tomato spotted wilt virus (TSWV), Impatiens necrotic spot virus (INSV), Groundnut ringspot virus (GRSV), Chrysanthemum stem necrosis virus (CSNV) and Tomato chlorotic spot virus (TCSV) (Whitfield et al., 2005). These viruses are acquired by the first-instar or early second-instar larvae when feeding on an infected plant, and are then transmitted only later when these larvae develop into the mobile adults;it is not possible for an adult to acquire and then transmit any of these viruses (Moritz et al., 2004). Virus symptoms vary considerably among plants, ranging from the disastrous wilting and collapse of lettuce plants, through a range of leaf mottling and distortions, to ring-spotting on tomato and capsicum fruits. These virus attacks can lead to the total loss of certain crops (see reviews in Kuo, 1996). F. occidentalis also transmits a carmovirus (Pelargonium flower break virus, PFBV) and may transmit an ilarvirus (Tobacco streak virus, TSV) (Jones, 2005).

Impact


Since the 1970s Frankliniella occidentalis has successfully invaded many countries to become one of the most important agricultural pests of ornamental, vegetable and fruit crops globally. Its invasiveness is largely attributed to the international movement of plant material and insecticide resistance, both of which have combined to foster the rapid spread of the species throughout the world (Kirk and Terry, 2003). Individuals are very small and they reside in concealed places on plants;thus are easily hidden and hard to detect in transported plant material. They reproduce rapidly and are highly polyphagous, breeding on many horticultural crops that are transported around the world.

Hosts

F. occidentalis is a highly polyphagous species with at least 250 plant species from more than 65 families being listed as 'hosts'. Unfortunately, the term 'host plant' is poorly defined in the literature on thrips. Plant species have sometimes been listed as 'hosts' simply because adults have been collected from them. The concept of 'host plant' is best restricted to those plants on which an insect can breed, and for many of the 250 plants from which F. occidentalis has been recorded there is little or no evidence of successful breeding. However, the association of adults with various plants has economic importance when viruliferous adults feed on susceptible plants. In its native range of the western USA, this thrips species can be found in large numbers on a very wide range of native plants, from lowland herbs to alpine shrubs and forbs. As a pest it is found both outdoors and in glasshouses, and it attacks flowers, fruits and leaves of a wide range of cultivated plants. These include apples, apricots, peaches, nectarines and plums, roses, chrysanthemums, carnations, sweet peas, Gladiolus, Impatiens, Gerbera and Ranunculus, peas, tomatoes, capsicums, cucumbers, melons, strawberries, lucerne, grapes and cotton. In northern Europe it is found particularly on glasshouse crops, such as cucumbers, capsicums, chrysanthemums, Gerbera, roses, Saintpaulia and tomatoes. In southern Europe it is extremely damaging to many field crops, including capsicums, tomatoes, strawberries, table grapes and artichokes, and at least in southern Italy, it has become a dominant member of the thrips fauna in wild flowers. Similarly, in Kenya the species has become a dominant member of the wild thrips fauna near agricultural fields. In contrast, in Australia it has not been found breeding on any native plant species. A further complication in considering its pest status is that in some areas this thrips species is an important predator of plant-feeding mites, such as on cotton in California, and it is then regarded as a beneficial (Trichilo and Leigh, 1986).


Source: cabi.org
Description

R. fistulosa is a broad-leaved, annual, facultative hemi-parasitic forb species found in wetlands in tropical Africa (e.g. Hansen, 1975;Ouédraogo et al., 1999). When these wetlands are used for crop production, the species may develop into a (parasitic) weed (Bouriquet, 1933;Rodenburg et al., 2011b).

Recognition

R. fistulosa is a relatively unknown species at present and therefore it is often unnoticed by local extension and research (as observed in Benin, Cote d’Ivoire, Madagascar, Senegal, Tanzania and Uganda). The species is also easily overlooked as the flowers are only opening at sunset (Cissé et al., 1996).
R. fistulosa can be confused with several species, including Cycnium recurvum (Oliv.) Engl. (previously named R. fistulosa recurva Oliv. and R. tenuisecta Standl.), which has a similar plant type and overlapping distribution in parts of North-East and South-East Africa. However, the tube of the corolla of C. recurvum is about one third of that of R. fistulosa. Moreover, C. recurvum has a distinctly different habitat, favouring dry conditions (Mielcarek, 1996).
The closely-related genera Rhamphicarpa and Cycnium are distinguished by the form of the capsules and the presence of a beak on their capsules: Rhamphicarpa have oblique ovoid capsules with beaks, whereas Cycnium have straight oblong capsules without a beak (Cycnium) (Staner, 1938).
Another distinctive feature is the stamens: Rhamphicarpa stamens are didynamous, arising at 2 levels in the corolla tube, and the style exceeds the stamens, whereas in Cycnium the style never exceeds the lower pair of stamens, and stamens are equal in length, arising at 1 level in the corolla tube (Philcox, 1990;Fischer, 1999;Leistner, 2005).
Due to their parasitic nature, and similarities in host crop ranges, local names given by farmers are often the same for both R. fistulosa and Striga spp. (J Rodenburg, personal observation). R. fistulosa is sometimes even referred to as ‘the Striga of rice’, even though both R. fistulosa and Striga spp. parasitize rice. Striga spp. are usually found on rice grown in the free-draining uplands, whereas R. fistulosa parasitizes rice in the water-logged lowlands and hydromorphic zones.

Impact

R. fistulosa is a broad-leaved, annual, facultative hemi-parasitic forb species very widespread in the wetlands of tropical Africa (Staner, 1938). It has also been reported in India, New Guinea and Australia. No hard evidence is published on the invasiveness of R. fistulosa. Although R. fistulosa is not yet considered to be a widespread problem, it has the potential to become more important in the near future (Raynal Roques, 1994;Rodenburg et al., 2010;2011a), especially since it can develop into a parasitic weed when it encounters a suitable host plant (e.g. Akoegninou et al., 1999). It parasitizes cereal crops like rice and there are indications that it is increasingly common on rain-fed lowland rice (Rodenburg et al., 2011b). Given its very widespread distribution (more than 35 countries in sub-Saharan Africa), the species is likely to be, or become, a very serious parasitic weed, threatening rice production in the continent.

Hosts

R. fistulosa parasitizes wild grass species (of the Poaceae family) and is a facultative hemi-parasitic weed on cereal crops like rice, maize and millet (Bouriquet, 1933;Kuijt, 1969;Cissé et al., 1996;Ouédraogo et al., 1999). Groundnut Arachis hypogaea L. (Bouriquet, 1933) and cowpea Vigna unguiculata (L.) Walp. (Kuijt, 1969) have been reported as hosts too, although the latter report concerned R. veronicaefolio Vatke (= Cycnium veronicifolium Vatke), rather than R. fistulosa (Fuggles-Couchman, 1935).
Rice, particularly direct seeded rice (Johnson et al., 1998), is the most affected crop, as this is the only major cereal crop that can be grown in the temporary flooded conditions of the rain-fed lowlands where R. fistulosa thrives (Rodenburg et al., 2010;2011b).
Supposedly R. fistulosa can also parasitize members of the monocot Cyperaceae as well as the eudicot Leguminosae and Labiatae families (Bouriquet, 1933). It is very unusual for a parasitic plant species to be able to parasitize both monocotyledons and eudicotyledons, and so these reports need to be confirmed.
R. fistulosa is a facultative hemi-parasite and as such it is not dependent on the presence of a host to complete its life cycle. However, the parasite obtains a reproduction advantage from parasitizing a suitable host plant (Ouédraogo et al., 1999;Rodenburg et al., 2011b).


Source: cabi.org
Host plants Halyomorpha halys
Description


Although somewhat variable in size and coloration, adult specimens of H. halys range from 12 to 17 mm in length, and in humeral width of 7 to 10 mm. The common name brown marmorated stink bug is a reference to its generally brownish and marbled or mottled dorsal coloration, with dense punctation. Detailed redescriptions and diagnoses of adults are provided by Hoebeke and Carter (2003) and Wyniger and Kment (2010). Eggs are smooth and pale in colour, approximately 1.3 mm in diameter by 1.6 mm in length, and are laid in clusters of 20-30. The brightly coloured, black and reddish-orange first instars remain clustered about the egg mass after hatching and move away once moulting to second instars has occurred. There are five nymphal instars, which are described in Hoebeke and Carter (2003) with a key and illustrated with colour photos.

Recognition

H. halys adults can be detected throughout the active growing season using blacklight traps and baited pheromone traps and nymphal populations can be detected with pheromone traps. However, each trap has limitations. Blacklight traps are attractive from early spring through September with reduced attractiveness as adults begin seeking overwintering sites. Baited pheromone trap effectiveness depends on the lure deployed. The use of methyl (2 E,4 E,6 Z)-decatrienoate only provides late season adult attractivess, whereas the use of (3 S,6 S,7 R,10 S)-10,11-epoxy-1-bisabolen-3-ol and (3 R,6 S,7 R,10 S)-10,11-epoxy-1-bisabolen-3-ol alone or in combination with methyl (2 E,4 E,6 Z)-decatrienoate provides season-long adult attractiveness.
In cropping systems, H. halys adults and nymphs can be detected through the use of timed visual counts, whole plant inspections, beat sheets counts and sweep netting. Timed visual counts are effective in field maize, nursery, nut, tree fruit and vegetable crops. Whole plant inspections are possible in various vegetables, field and sweetcorn by inspecting a specified number of plants per field or through the use of counts per linear foot of row. Beat sheet counts can be employed in nursery, nut and tree fruit;however, they are discouraged in nuts and tree fruit after thinning or June drop has occurred due to the potential removal of fruit. Sweep netting can be used in soyabeans but should be confined to field borders.
H. halys adults seek concealed, cool, tight and dry locations to overwinter. Because of this overwintering behaviour and need for specific microhabitats, many suitable sites can be generated by human-made materials and used by this insect as an overwintering sites such as inside cardboard boxes, other shipping containers and luggage, between wooden boards, within layers of folded tarps, and within machinery motors and vehicles. Thus, inspection for H. halys in shipments of goods from areas where it is present will require thorough visual inspections.

Symptons


Adults and nymphs cause feeding damage. On tree fruits, feeding injury causes depressed or sunken areas that may become 'cat-faced' as the fruit develops. Late season injury causes corky spots on the fruit. Feeding may also cause fruiting structures to abort prematurely. Similar damage occurs in fruiting vegetables such as tomatoes and peppers, although frequently later in the season. Feeding can cause failure of seeds to develop in crops such as maize or soyabean. There is frequently a distinct edge effect in crop plots as H. halys has an aggregated dispersion and moves between crops or woodlots. In soyabeans, this can result in a 'stay green' effect where pods fail to senesce at the edges due to H. halys feeding injury.

Impact


Following the accidental introduction and initial discovery of H. halys in Allentown, Pennsylvania, USA, this species has been detected in 41 states and the District of Columbia in the USA. Isolated populations also exist in Switzerland, France, Italy and Canada. Recent detections also have been reported in Germany and Liechtenstein. BMSB has become a major nuisance pest in the mid-Atlantic region and Pacific Northwest, USA, due to its overwintering behaviour of entering human-made structures in large numbers. BMSB also feeds on numerous tree fruits, vegetables, field crops, ornamental plants, and native vegetation in its native and invaded ranges. In the mid-Atlantic region, serious crop losses have been reported for apples, peaches, sweetcorn, peppers, tomatoes and row crops such as field maize and soyabeans since 2010. Crop damage has also been detected in other states recently including Oregon, Ohio, New York, North Carolina and Tennessee.

Hosts

H. halys has over 100 reported host plants. It is widely considered to be an arboreal species and can frequently be found among woodlots. Such host plants are important for development as well as supporting populations, particularly during the initial spread into a region. In Canada for example, established populations of H. halys have only been recorded in the Province of Ontario. Homeowner finds have previously been identified in the City of Hamilton (Fogain and Graff, 2011) as well as the Greater Toronto Area, the City of Windsor, Newboro and Cedar Springs (Ontario) (Fraser and Gariepy, unpublished data). However, preliminary surveys confirmed an established breeding population in Hamilton, Ontario, as of July 2012 (Fraser and Gariepy, unpublished data). At present, these populations are localized along the top of the Niagara escarpment in urban/natural habitats within Hamilton, and have not yet been recorded in agricultural crops. Reproductive hosts from which H. halys eggs, nymphs and adults have been collected on in Ontario include: ash, buckthorn, catalpa, choke cherry, crabapple, dogwood, high bush cranberry, honeysuckle, lilac, linden, Manitoba maple, mulberry, rose, tree of heaven, walnut and wild grape (Gariepy et al., unpublished data).
The list of host plants in Europe contains 51 species in 32 families, including many exotic and native plants. High densities of nymphs and adults were observed on Catalpa bignonioides, Sorbus aucuparia, Cornus sanguinea, Fraxinus excelsior and Parthenocissus quinquefolia (Haye et al., unpublished data).
Multiple host plants seem to be important for development and survival of H. halys. This species can complete its development entirely on paulownia (Paulownia tomentosa), tree of heaven (Ailanthus altissima), English holly and peach. More details on host plants and host plant utilization can be found at http://www.stopbmsb.org/where-is-bmsb/host-plants/ as well as http://www.halyomorphahalys.com, Panizzi (1997), Nielsen and Hamilton (2009b) and Lee et al. (2013a).
In Asia, H. halys is an occasional outbreak pest of tree fruit (Funayama, 2002). Damage to apples and pears in the USA was first detected in Allentown, Pennsylvania, and Pittstown, New Jersey (Nielsen and Hamilton, 2009a). In orchards where H. halys is established in the USA, it quickly becomes the predominant stink bug species and, unlike native stink bugs, is a season-long pest of tree fruit (Nielsen and Hamilton, 2009a;Leskey et al., 2012a). In particular, peaches, nectarines, apples and Asian pears are heavily attacked. Feeding injury causes depressed or sunken areas that may become cat-faced as fruit develops. Late season injury causes corky spots on the fruit. Feeding may also cause fruiting structures to abort prematurely. Similar damage occurs in fruiting vegetables such as tomatoes and peppers, although frequently later in the season. Feeding can cause failure of seeds to develop in crops such as maize or soyabean. There is frequently a distinct edge effect in crop plots as H. halys an aggregated dispersion and moves between crops or woodlots. In soyabeans, this can result in a 'stay green' effect where pods fail to senesce at the edges due to H. halys feeding injury.


Source: cabi.org
Description

A. raddianum is a fern with a short-creeping and irregularly-branched rhizome up to 50 mm long and ca 2 mm wide. The rhizome and the bases of the frond stalks are covered with dark-brown scales of less than 1 mm length. Fronds are arched to erect, 10-50 cm long and 6-20 cm wide, and triangular in shape. Frond stalks and axes are dark reddish-brown to blackish and shining. The frond stalk is usually longer than the lamina. Laminas are 3-4-pinnately divided, with the ultimate segments delicate, herbaceous and up to 1 cm wide. Ultimate segments are wedge-shaped and have slender red-black stalks. Segments of sterile fronds, if present, are larger than fertile fronds. Spore cases (sori) are 'U'-shaped and arranged either at the edge of veins or at their tips and less than 4 mm wide. Each sorus is covered with a pale or whitish membrane (indusium).

Impact

A. raddianum is a delicate fern native to tropical and subtropical South America. The fern grows terrestrially or on rocks and erects arching fronds, up to 50 cm high, growing out of a short rhizome. The plant has become naturalized in various tropical and subtropical islands and is considered to be invasive in Hawaii and French Polynesia. The fern readily spreads and becomes locally abundant. In Hawaii it was first observed around 1910 and is now the most common Adiantum species. It grows best in moist and shady places and appears to replace the closely related native Adiantum capillus-veneris. It also threatens an endemic species of silversword, Dubautia plantaginea subsp. humilis, and another native fern, Pteris lidgatei.


Source: cabi.org
Description

The following description comes from Burger and Huft (1995)

Impact

C. argenteus is an herbaceous weed of open sunny sites, pastures, and agricultural lands. It is also a common weed in rice plantations (González, 2000). Because this species grows in seasonally waterlogged areas, its seeds are often dispersed as a contaminant in dried and wet mud (Standley and Steyermark, 1946). Currently, it is listed as invasive only in Cuba, but it is a common weed in dry and wet fields in areas within and outside its native distribution range (Oviedo Prieto et al., 2012;USDA-NRCS, 2015).

Hosts

C. argenteus is a weed of pastures and rice and sugarcane plantations (Standley and Steyermark, 1946;González, 2000;Torres et al., 2010).


Source: cabi.org
Description

E. paniculata usually grows as an annual or short-lived perennial plant. It is rooted in mud in shallow waterways. Submersed sessile leaves form a basal rosette and are linear to oblanceolate. Petiolate leaves are above the water surface with a cordate blade, acuminate to acute at the tip. Petiolate leaf blades grow 7.5-15 cm long, 3.5 – 9 cm wide, and the petiole may be up to 60 cm long. The flowers grow on separate flowering stalks in a panicle with 5-100 flowers developing over several days. The peduncle is sparsely glandular-pubescent to glabrous, 11.5-17.5 cm long;spathe linear, 13-35 mm long, the apex acuminate. Flowers are blue, white or lilac. The floral tube is 8-10 mm long, tepals are 12-15 mm long. The central upper tepal has two yellow spots toward the base. Upper and lower stamens are 2.5-3.5 mm and 5.1-8.5 mm long respectively. Stigmas are 3-lobed and tristylous. Seeds form in capsules 6-8mm long. Seeds are 0.6-1.0 mm long, 0.6-0.8 mm wide with 10-12 longitudinal wings (Barrett and Husband, 1997;Flora of the Guianas, 2016).

Impact

Eichhornia paniculata can grow in monocultural stands in shallow wetlands (Barrett and Husband, 1997). It is listed as a transformative species in Cuba by Oviedo-Prieto et al. (2012), although other sources suggest that it is native to Cuba (FreshFromFlorida, 2016). Listed as a prohibited aquatic plant in Florida along with all species of Eichhornia (USDA-NRCS, 2016), because of the invasive nature of other species in the genus. It appears to have naturalized only in Guyana (Funk et al., 1997) and is listed as an agricultural weed of rice fields in Jamaica and Cuba (Barrett, 2011).

Hosts

A weed of rice fields in Jamaica and Cuba (Barrett, 2011).


Source: cabi.org
Description

G. spilanthoides is an aquatic perennial that can form rounded bushes up to 1-1.5 m tall or scrambling mats of tangled stems. The plant can grow in various forms, producing runners and floating stems up to 2.5 m in length or growing as rounded bushes or extending from the banks, in mats of tangled stems reproducing vegetatively and by seed (Csurhes and Edwards, 1998). The following description is from Parsons and Cuthbertson (1992).

Impact

G. spilanthoides is an emergent freshwater or marsh-growing perennial which can form rounded bushes up to 1-1.5 m tall or scrambling mats of tangled stems along the edges of waterways. It grows very rapidly, up to 15 cm per week, and floating mats cover water bodies, blocking drainage channels and degrading natural wetlands by displacing native plants and animals as well as detracting from their environmental value, natural beauty and recreational potential. In New Zealand, it has caused flooding by blocking streams and drainage channels, and it could potentially infest wetlands throughout much of Australia. It has a wide climate tolerance and has been found in cultivation well outside its predicted range, and has the ability to continue growing even when completely submersed although growth rates are reduced and plants are smaller. It is also very difficult to control because it can spread by both seed and vegetative reproduction, and even tiny pieces of vegetation can give rise to new colonies.


Source: cabi.org
Description


Primarily from Clayton et al. (2014) and Cowie et al. (2000), with minor additions from Florida collections:
Habit

Recognition


Diagnostic features of the genus Hymenachne include its aquatic habit and lower internodes filled with spongy aerenchyma, the cylindrical inflorescence, the margins of the upper lemma being flat and the glumes not saccate (Webster, 1987). In Australia, the genus is ultimately characterized from other Panicae by the first glume which encircles the spikelet base (Webster, 1987).
Commodity inspectors should be wary of contamination in rice seed, especially rice grown in Central and South America or Louisiana, USA. Inspectors should look for the spikelets, which are light in colour, flattened, and only a few millimetres long;the actual seed/fruit (caryopsis) is too small to detect with the unaided eye.
A trained botanist having intact, mature spikelets may find them possible to identify using the illustration provided (see Images, above) and the following characters:
1) Lower glume wrapping the base of the spikelet and small, appearing only 1.3 as long as the spikelet and wedge shaped at the tip, 3-5 nerved and scabrous on the keel.
2) Lower lemma 3.6-4.6 mm, 5 nerved and tapering gradually to a long point, longer than the fruit, margins flat, and scabrous on the nerves.
3) Upper glume 2.8-3.9 mm long, 5 nerved and scabrous on the nerves.
Vegetative material may be less likely to be transported, but is easier to recognize. Use the illustration above to focus on:
1) Leaf blade flat with base auriculate and clasping
2) Leaf glabrous except for the base having a few long hairs
3) Stems solid
4) Nodes with adventitious, spongey roots

Impact

H. amplexicaulis is a perennial, stoloniferous, freshwater grass that forms monospecific stands in seasonally flooded environments of tropical, subtropical, and warm temperate climates. It is native to Central and South America, where populations have increased around human disturbance. H. amplexicaulis has been introduced to the USA and Australia, where both countries first observed its invasive abilities in the 1990s. Robust, long lived, tolerant to hydrological fluctuation, and able to spread locally by fragments and across distances by seed, H. amplexicaulis is capable of displacing native species and altering indigenous communities under natural regimes. It is known to hinder irrigation, drainage and hydroelectric systems in agricultural and urbanized systems. It has also corrupted indigenous genotypes by hybridizing with a native Australian congener to form the morphologically intermediate hybrid H. x calamitosa. H. amplexicaulis was ranked by the Florida Exotic Pest Plant Council as a Category I invasive due to the ecological damage it has caused. In Australia, it is prohibited as a Class 2 Declared Pest and named a Weed of National Significance for its proven potential to invade wet areas across a wide geographic range.

Biological Control
<br>An effective biological control agent has not been determined for H. amplexicaulis, although studies have been made.<br>The sap-feeding bug Ischnodemus variegatus, discovered on H. amplexicaulis in Florida, has been found to reduce the plant’s growth rate and biomass (Overholt et al., 2004). I. variegatus is predicted to complete three to five generations per year in areas where its host plant has invaded Florida (Diaz et al., 2008). Laboratory studies found that it developed and survived best on H. amplexicaulis (23.4% survival) than on other genera tested (Diaz et al., 2009) and that it performed poorly overall on H. acutigluma when compared to H. amplexicaulis (Diaz et al., 2010).<br>An undescribed Delphacidae species found naturally occurring on H. acutigluma in Australia did not occur nearby on H. amplexicaulis and did not develop on H. amplexicaulis in laboratory tests. The insect species proved to be host specific to H. acutigluma, causing yellowing and weakening of that species under high densities in the laboratory (Bell et al., 2011).

Source: cabi.org
Host plants Hyptis brevipes Long
Description

H. brevipes is an erect annual plant up to 1 m high with a square stem typical of the family, often densely hairy but sometimes less so. Leaves are also normally coarsely hairy on both surfaces, opposite, narrowly ovate or lanceolate, 4-7 cm long, up to 2 cm wide, cuneate at the base, the margins irregularly serrate. Apex acute to acuminate. The inflorescence is a dense raceme, almost globose, up to 14 mm diameter, on a peduncle about 1 cm long in the axils of most upper leaves. Corolla white or purplish-white, irregularly five-lobed about 5 mm long. The calyx, 4 mm long, also has 5 narrow, finely barbed lobes. Bracts lanceolate, 8-12 spreading or reflexed, 4-6 mm long, almost concealed by the flowers. Seeds ovoid, up to 1 mm long, dark brown to black, obscurely striate, with a conspicuous scar.

Impact

H. brevipes is an annual plant of cultivated land and wastelands, including forest edges, wet ground and rice crops, and is favoured by continuous wet conditions, without a prolonged dry season. It is native to Mexico, the Caribbean and much of South America and has been widely introduced across South East Asia, where it has naturalized. H. brevipes may be accidentally introduced into a new area as a contaminant of seed, in particular with rice. It has been listed as a ‘principal’ weed of Malaysia and a common weed of Borneo, Philippines and Taiwan (Holm et al., 1979). In addition, PIER (2017) report that H. brevipes is invasive in Singapore, Thailand and Vietnam. Lorenzi (1982) describes it as a damaging weed of humid conditions along the coast, where it can develop into large infestations. H. brevipes is typically a weed of agricultural land, causing yield losses and a negative economic impact.

Hosts

H. brevipes is primarily a weed of rice, especially in South East Asia, including Malaysia (Yong and Goh, 1977). In Indonesia it is noted to be a weed in rain-fed and upland rice fields, grasslands, rubber, cacao, young oil palm and sugar cane plantations and orchards (Knowledge Management Center on Topical Biology, 2017). It is also listed among weeds in mung bean in Indonesia (Bangun et al., 1986) and in Phaseolus beans in Brazil (Laca-Buendia et al., 1989).


Source: cabi.org
Host plants Lantana camara
Description

L. camara is a medium-sized perennial aromatic shrub, 2-5 m tall, with quadrangular stems, sometimes having prickles. The posture may be sub-erect, scrambling, or occasionally clambering (ascending into shrubs or low trees, clinging to points of contact by means of prickles, branches, and leaves). Frequently, multiple stems arise from ground level. The leaves are generally oval or broadly lance-shaped, 2-12 cm in length, and 2-6 cm broad, having a rough surface and a yellow-green to green colour. The flat-topped inflorescence may be yellow, orange, white, pale violet, pink, or red. Flowers are small, multicoloured, in stalked, dense, flat-topped clusters to 4 cm across. Fruit is a round, fleshy, 2 seeded drupe, about 5 mm wide, green turning purple then blue-black (similar in appearance to a blackberry).

Recognition

L. camara is conspicuous due to its attractive and multicoloured floral displays and is a well-known species throughout the tropics.

Impact

L. camara is a highly variable ornamental shrub, native of the neotropics. It has been introduced to most of the tropics and subtropics as a hedge plant and has since been reported as extremely weedy and invasive in many countries. It is generally deleterious to biodiversity and has been reported as an agricultural weed resulting in large economic losses in a number of countries. In addition to this, it increases the risk of fire, is poisonous to livestock and is a host for numerous pests and diseases. L. camara is difficult to control. In Australia, India and South Africa aggressive measures to eradicate L. camara over the last two centuries have been largely unsuccessful, and the invasion trajectory has continued upwards despite control measures. This species has been the target of biological control programmes for over a century, with successful control only being reported in a few instances.

Hosts

L. camara is an agricultural weed that can cause dramatic losses in yields. In Australia, it was reported that L. camara infested 4 million ha of pasture (Parsons and Cuthbertson, 1992). A number of plants affected by L. camara are listed in the "Host Plants/Plants Affected" table below.


Source: cabi.org
Description

L. peploides is an emergent and floating herbaceous perennial macrophyte. It has glabrous or pubescent stems 1-30 dm that can creep horizontally as well as grow vertically. Early growth resembles a rosette of rounded leaves growing on the water’s surface. Alternate leaves are polymorphic and less than 10 cm long and oblong to round, often lanceolate at flowering. The species exhibits root dimorphism and has adventitious roots that form at nodes and ensure oxygen uptake. Flowers are 5-merous (pentamerous), grow from leaf axils, are bright yellow, and can be from 7 to 24 mm long. Fruit is in a five-angled reflexed capsule, about 3 cm long that contains 40-50 seeds 1.0-1.5 mm long, embedded in the inner fruit wall (EPPO, 2004;The Jepson Online Interchange, 2009).

Impact

L. peploides is a productive emergent aquatic perennial native to South and Central America, parts of the USA, and likely Australia (USDA-ARS, 1997). It was introduced in France in 1830 and has become one of the most damaging invasive plants in that country (Dandelot et al., 2008). It is often sold as an ornamental, which likely explains its introduction to Europe. It has been more recently introduced to areas beyond its native range in the USA, where it is often considered a noxious weed (INVADERS, 2009;Peconic Estuary Program, 2009). L. peploides is adaptable, and tolerates a wide variety of habitats where it can transform ecosystems both physically and chemically. It sometimes grows in nearly impenetrable mats;it can displace native flora and interfere with flood control and drainage systems, clog waterways and impact navigation and recreation (Peconic Estuary Program, 2009). The plant also has allelopathic activity that can lead to dissolved oxygen crashes, the accumulation of sulphide and phosphate, ‘dystrophic crises’ and intoxicated ecosystems (Dandelot et al., 2005).

Hosts

Impacts on the local environment by L. peploides can be devastating. The species possesses an allelopathic activity that has year-long effects on water quality and can lead to impoverished flora by decreasing seedling survival of vulnerable native taxa (Dandelot et al., 2008). L. peploides can also cause severe hypoxia and sometimes anoxia during the summer. It can also lead to reduced sulphate and nitrate levels and increased sulphide and phosphate concentrations. These combined effects have the capability of fomenting what Dandelot et al. (2005) refer to as “a dystrophic crisis” and an intoxicated ecosystem. The plant has been reported to outcompete native Myriophyllum and Potamogeton species in France, which translates to a reduction in macroinvertebrate habitat (Dutartre, 1986;CEH, 2007). It also supplants native wetland grasses, some of which are used as forage for livestock (CEH, 2007).


Source: cabi.org
Description

L. japonicum is a rhizomatous vine, climbing to 30 m. Rhizomes creeping, with black to reddish-brown hairs. Stipes spaced to 1 cm apart on rhizome. Rachis grooved, pubescent to glabrous, 3-30 m. Pinnae with short stalks, 3-5 cm. Pinnae deltoid shaped, 2-3-pinnate, to ca. 12 cm long, 12 cm wide, usually with a long central lobe, margins lobulate. Costae with scattered hairs, veins and pinnae surfaces typically glabrous, rarely with short hairs. Fertile segments with 3-5 separate lobes, subpalmate, sporangia born on sorophores, each with 4-8 sporangia pairs. Spore diameters 64-80 µm, averaging 76 µm.

Recognition


When mature, L. japonicum is easily detected on the ground due to its unique morphology and high-climbing habitat. However, because the species can disperse easily into remote areas via windborne spores new populations are easily overlooked because of difficulty of access.

Impact

L. japonicum is a high-climbing vine that has become established outside of its native range of Asia. L. japonicum is widely cultivated around the world. In the 1900s it became established in the south east USA and has since spread to at least nine states. L. japonicum occupies most of the southeastern coastal plain and parts of the Piedmont. Outside of its native range, L. japonicum has become an invasive species in a variety of habitats;floodplain forests, marshes and other wetlands, pine flatwoods, timber plantations and disturbed sites. It is a threat to natural areas where it outcompetes native species, alters fire behaviour and also poses an economic threat to the timber and pine straw industries. The distribution of the species continues to expand and could eventually occupy 39% of the USA;it has not yet reached the limit of distribution and abundance (USDA, 2009). Populations of L. japonicum have also become established on two Hawaiian Islands, Puerto Rico, Singapore and South Africa. Here, the species has not spread as aggressively as in the USA, but is of major concern.

Hosts


In the Philippines L. japonicum has been listed as a weed of upland rice (Moody, 1989;Galinato et al., 1999).
In southeastern USA it is an invader of pine plantations (Pinus spp.) (Beasley and Pijut, 2010).

Biological Control
<br>The potential for biocontrol of Lygodium species has been a subject of active research due to the invasiveness of two species in the genus in the USA: L. japonicum and L. microphyllum (Ferriter, 2001). While biocontrol agents have been released for L. microphyllum, no agents have been released specifically for L. japonicum. Finding a biocontrol suitable for this species will be difficult due to the sympatric, native species L. palmatum.<br>In 2005 a moth, Austromusotima camptozonale, was released in Florida for the control of L. microphyllum but failed to establish (Langeland and Hutchinson, 2013). A second species of moth Neomusotima conspurcatalis (Lygodium defoliator moth) was released in peninsular Florida in 2008 and 2009 as a biocontrol of L. microphyllum and populations have become established (Langeland and Hutchinson, 2013). This moth is genus specific and also feeds on L. japonicum, however, it is sensitive to cold temperatures. It was approved for release because of this characteristic as it will not pose a threat to the temperate native L. palmatum. While there are populations of L. japonicum in frost-free areas that will be impacted by N. conspurcatalis, populations outside of Florida will not be in the range of the moth (Madeira et al., 2008;Boughton et al., 2009). A second species in the genus, N. fuscolinealis, was also screened however it was rejected as it posed a threat to L. palmatum (Bennett and Pemberton, 2008).

Source: cabi.org
Host plants Merremia aegyptia Long
Description

Herbaceous, twining or creeping vine, attaining 3 m or more in length. Stems cylindrical, usually reddish, with long, erect, yellowish, non-glandular hairs. Leaves alternate, 5-palmately compound;leaflets 4-14 x 2-6 cm, oblanceolate or elliptical, the apex and base acuminate, the margins entire and ciliate, hispidulous to glabrate on both surfaces. Flowers in dichasial cymes;peduncles shorter than the petioles, hairy;bracts deciduous;sepals subequal or unequal, 1.5-2 cm long, with long, yellowish hairs;corolla funnel-shaped, white, 2.5-3 cm x 4-4.5 cm;five stamens, white;stigma bilobed, white. Fruit capsular, 4-valvate, subglobose, 1-1.5 cm in diameter, light brown, glabrous, surrounded by the persistent sepals. Four seeds per fruit, obtusely triangular, 5-6 mm long, brown, glabrous (Acevedo-Rodríguez, 2005;Austin et al., 2012).

Recognition

M. aegyptia can be easily recognized in the field by the 5-digitate leaves with entire leaflets, and the long, erect hairs covering the stems and calyx.

Impact

Merremia aegyptia is an annual climbing herb that acts as a pioneer species in disturbed sites in tropical regions. It is considered a weed in most countries where it occurs and it has been included in the Global Compendium of Weeds as an agricultural and environmental weed (Randall, 2012). The species is native to tropical America and Africa and listed as invasive in Cuba, India, Australia and Hawaii.

Hosts

M. aegyptia is a relatively common weed in sugarcane (Brazil, Lesser Antilles, Reunion) and maize fields (Guatemala, Brazil, Nigeria), where it climbs up plants, bending and entangling their stems (Standley and Williams, 1970;Fournet and Hammerton, 1991;Lima e Silva et al., 2004;Valery, 2006;Chikoye et al., 2009;Correia et al., 2010;Correia, 2016). It has also been reported in cotton (Cardoso et al., 2010), banana (Isaac et al., 2009), rice (Ismaila et al., 2015), green pepper (Coelho et al., 2013), muskmelon (Teófilo et al., 2012), yam (Fournet and Hammerton, 1991) and coffee plantations (Gavilanes et al., 1988).


Source: cabi.org
Description

The following description is taken from Flora of North America Editorial Committee (2016)

Impact

N. lotus is a floating leafed macrophte and water lily, native to Africa and specific areas in Europe. It has a number of medicinal properties and is often introduced into new areas as an ornamental. This species has become naturalized in North America and some countries in South America and Asia, but no published reports of it being invasive were found other than presence (without further details) on an invasive species list for Louisiana (Louisiana Department of Wildlife and Fisheries, 2015). There are limited reports of the impact of this species, although in newly reclaimed wetlands in the Nile Delta, Egypt, N. lotus has been observed colonizing rice fields causing a significant decrease in growth and yield. Khedr and Hegazy (1998) describe it here as having "rampant behaviour as an aquatic weed invading the newly reclaimed ricefields," with its aggressiveness related to being able to spread through both vegetative and sexual reproduction.

Hosts

N. lotus is recorded as a weed in rice fields in Egypt where it can significantly reduce the growth and grain yield of the crop (Khedr and Hegazy, 1998;Hegazy et al., 2001).


Source: cabi.org
Description


Description taken from GrassBase (Clayton et al., 2006) with minor modifications from Godfrey and Wooten (1979) and from material reviewed by the author

Recognition


Separating P. geminatum from other tribes of grasses:
P. geminatum is perennial, does not form a winter rosette, and its basal leaves do not differ from stem leaves. The infloresence consists of several spike-like racemes along a main axis;rachis of racemes somewhat flattened, ending in a short, naked point (not a bristle);spikelets glabrous, fruits transversely rugose.
Separating P. geminatum from other Panicum in the tribe Geminata:
P. geminatum is glabrous throughout, nodes glabrous. Spikelets to 3.3 mm;glumes and sterile lemma not papery.
Determining P. geminatum:
The ligule is a ring of hairs to 1 mm long. Leaf sheaths compressed. Leaf blades flat medially, linear, the long-tapering tips involute;blades mostly glabrous or with minute hairs at base of upper surface. Infloresence up to 30 cm long and bearing 6 to 20 alternating, short-ascending or appressed-ascending flattish, spike-like fertile branches. The rachis is sharply 3-angled and ends in a short naked point, not a bristle. Spikelets planoconvex or nearly so, 2.2 to 3.3 mm long, arranged alternately in two rows on one side of the sharply 3-angled rachis. Spikelets are ovate to oblong-elliptic in shape. The first glume is short, as broad as it is long or broader than it is long.

Impact

P. geminatum is a globally-distributed grass that is an important component of marshes and emergent grasslands in tropical, dry, and warm temperate climates defined by well-marked dry and rainy seasons. P. geminatum contributes to unique and diverse wetland communities. It can become locally abundant under extended warm season flooding, but is not considered introduced, invasive, or problematic in these natural environments. P. geminatum has become problematic in arid climates where urbanization, irrigation and drainage projects have caused massive alterations in soil and hydrologic regime. It can spread through irrigation canals, open waste ditches and polluted riparian systems, compromising water flow and flood control.


Source: cabi.org
Description

S. indica is a tufted mostly glabrous annual that can grow to 0.6 m high.

Recognition


As the only cosmopolitan species within the genus, S. indica is best described by length of its spikelet, the length if its upper glume, the length of the inferior lemma, the length of its anther upper flower, its hyaline ligules and its having an apex acute upper glume (Gennaro and Scataglini, 2012). Simon (1972) wrote that it is ‘characterized by a spikelet containing two florets of which the lower is male or barren, and the upper hermaphrodite. It is delimited from the type genus Panicum by the strongly saccate nature of the base of the upper glume and to a lesser extent of the lower lemma, and by the inflorescence... being a false spike (morphologically a much contracted panicle)’ (Simon, 1972). S. indica can also be distinguished from the rest of Paniceae by the presence of spiciform panicle with ribbed glumes and gibbous upper glumes (Teerawatananon et al., 2011).
S. indica is very similar to other Sacciolepis species such as S. spiciform (Flora Zambesiaca, 1989). Flora Zambesiaca conserves that S. indica ‘ can usually be distinguished by spikelet length and habit, but absence of leaf papillae is the most reliable character though it requires use of a microscope.’ Spikelet length and smooth pedicels can be used to quickly distinguish S. indica from S. myosuroides (Simon and Alfonso, 2012).
African specimens of S. indica often have little auricles. These specimens have been described as S. auriculata in the past. However, according to Flora Zambesiaca (1989), S. indica intergrades completely from forms with auricles to the commoner form that lacks auricles (Scholz, 1980;Flora Zambesiaca, 1989).

Impact

S. indica is an annual C3 grass (Aliscioni et al., 2003;De Gennaro, 2011). It is highly variable in size, spikelet length and pubescence, and it flowers sporadically throughout the year (Simon and Alfonso, 2012). S. indica is found in tropical and subtropical rainforests, tropical and subtropical sub-humid woodlands, and coastal grasslands.


Source: cabi.org
Description

S. verticillata is an annual, or more usually perennial. Stems straggling, to 100 cm or more, glabrous or nearly so, usually erect and simple or sparsely branched, often copiously branched from the base, usually 40 cm high or less, the stems tetragonous. Stipule sheath very short, the setae about 1.5 mm long;leaves glabrous, sessile or nearly so, linear or lanceo-linear, mostly 1.5-4 cm long and 1.5-6 mm broad, commonly 1-veined, often with fascicles of smaller leaves in the axils. Flowers white, very small in sessile clusters at the upper stem nodes or more usually terminal, then the heads subtended by 2 or 4 leaf-like bracts. Hypanthium pilose above, the 2 sepals narrowly triangular, 1.5 mm long or less. Corolla of 4 petals, 3 mm long, hispidulous outside at the apex, the lobes about equalling the tube;anthers exserted. Capsule 2.5 mm long;seeds reddish brown about 1 mm long (PIER, 2016).

Impact

S. verticillata is a scrambling annual or perennial native to the Americas. It has been introduced widely but sporadically across Asia and the Pacific and to tropical Australia. It can grow on a wide range of land types but often requires disturbance to establish. S. verticillata can form large clumps which can smother other vegetation. In its native range it has been recorded as a significant weed of agricultural crops, for example in the Caribbean it is a problem of sugarcane, vegetables and root crops (Fournet and Hammerton, 1991). In addition to this, on St Helena, it is among the exotic plants threatening the critically endangered fern, Pteris adscensionis.

Hosts


In a number of countries S. verticillata has been shown to have a negative impact on agricultural crops such as Coffea arabica, Oryza sativa, Phaseolus vulgaris, Saccharum officinarum, Theobroma cacao, Vigna unguiculata Manihot esculenta and Zea mays (Fournet and Hammerton, 1991;Holm, 1997;Johnson, 1997;Marques et al., 2011;Cherigo et al., 2012).


Source: cabi.org
Description


Ultrastructural aspects of AY group phytoplasmas in sieve tube elements of diseased plants have been studied by several researchers using transmission and scanning electron microscope observations (Hirumi and Maramorosch, 1973;Haggis and Sinha, 1978;Marcone et al., 1995;Marcone and Ragozzino, 1996;Fránová and Šimková, 2009;Fránová et al., 2009). The phytoplasma bodies varied in size and shape. They showed a very high polymorphism, appearing in round, ovoid, encurved and elongated forms. Octopus-like structures, as well as budding, dimpled- and dumbbell-shaped forms were also observed. The size of spherical forms ranged from 100 to 800 nm and filamentous bodies were up to 2600 nm in length. However, the morphological variations observed most probably represented various developmental stages of phytoplasmas and they cannot be considered as distinctive characteristics.

Recognition


For reliable diagnosis, the identity of phytoplasmas occurring in plants characterized by the symptoms described (see Symptoms), should be determined by molecular techniques.

Symptons


AY group phytoplasmas affect plants by causing extensive abnormalities in plant growth and development, suggestive of profound disturbance in plant hormone balance. Symptoms typical on herbaceous plant hosts include yellowing of the leaves, stunting, proliferation of auxiliary shoots resulting in a witches'-broom appearance, bunchy appearance of growth at the ends of stems, virescence of flowers and sterility, phyllody, shortening of internodes, elongation and etiolation of internodes, small and deformed leaves. Yellowing, decline, sparse foliage and dieback are predominant in woody plant hosts. However, it is well-known that distantly related phytoplasmas can cause identical symptoms in a given host plant, whereas closely related phytoplasmas can cause distinctly different symptoms. Lee et al. (1992) determined that different symptoms could be induced in Catharanthus roseus (periwinkle) by closely related strains of the AY phytoplasma group.

Hosts


AY group phytoplasmas appear to have a wide host range. The vast majority of strains in the AY group infect herbaceous dicotyledonous plant hosts. However, a number of strains that belong to subgroups 16SrI-A, 16SrI-B and 16SrI-C are capable of infecting monocotyledonous plants (e.g., maize, onion, gladiolus, oat, wheat and grass). Some strains in subgroups 16SrI-A, 16SrI-B, 16SrI-D, 16SrI-E, 16SrI-F and 16SrI-Q can induce disease in woody plants (e.g., grey dogwood, sandalwood, blueberry, mulberry, peach, cherry, olive, grapevine and paulownia). For many of the plant hosts which have previously been reported to be affected by AY diseases on the basis of symptomatology and/or microscopic examinations (see McCoy et al., 1989), the identity of the infecting phytoplasmas has never been determined with molecular techniques, or proved to be different from that of other established AY phytoplasma strains (Schneider et al., 1997;Marcone et al., 2000).


Source: cabi.org
Host plants Cornu aspersum
Description

C. aspersum is a large-sized land snail, with a shell generally globular but sometimes more conical (higher spired) and rather thin in the common form when compared to other Helicinae. The umbilicus is usually completely closed by a thickened white reflected lip that defines the peristome in adult snails. The shell is sculptured with fine wrinkles and rather coarse and regular growth-ridges and is moderately glossy because of a fine periostracum. The peristome is roundly lunate to ovate-lunate. Adult shells (4½ to 5 slightly convex whorls) measure 28-45 mm in diameter, 25-35 mm in height (Kerney and Cameron, 1979). The shell ground colour is from yellowish to pale brown. The shell also shows from zero to five reddish brown to blackish spiral bands superimposed on the ground colour and usually interrupted such that the ground colour appears as yellow flecks or streaks breaking up the bands;the bands are occasionally separated by a median white spiral line (fascia albata). Fusion of two or more adjacent bands and diffusion of band pigment on the whole shell surface are often observed. Frequently, the upper half of the shell is darker because of the effect of a dominant factor (Albuquerque de Matos, 1985). The banding pattern is much less distinct and more broken than that exhibited by the well-known polymorphic snails Cepaea nemoralis and Cepaea hortensis.

Recognition


The following information is from the Canadian Food Inspection Agency Cornu aspersum fact sheet (CFIA, 2014).
Indications of an attack by C. aspersum are ragged holes chewed in leaves, with large veins usually remaining;holes in fruit;and slime trails and excrement on plant material.
Adults and larger juveniles are likely to be visible among the host material or attached to the transporting containers. They may also be hidden in protected locations, sealed into their shells to avoid desiccation. Check the undersides of containers and their rims. Small snails and eggs in soil could be difficult to find. C. aspersum hides in crevices and will overwinter in stony ground.
Inspections are best carried out under wet, warm and dark conditions. Under bright, dry conditions it is necessary to thoroughly search dark, sheltered areas where the humidity is elevated, such as under low-growing plants or debris. The snails may bury themselves in loose soil or other matter, so the only way to be reasonably sure an area is not infested is to make repeated surveys over a long period of time.

Symptons

C. aspersum causes extensive damage in orchards (creating holes in fruit and leaves) and to vegetable crops, garden flowers and cereals.
In California, USA, populations established in citrus groves feed essentially on the foliage of young citrus and also on ripe fruits, creating small holes allowing the entry of fungi and decay of the fruit (see Pictures). Larger holes result in fruit dropping from the tree or being rejected for consumption during sorting and packing (Reuther et al., 1989;Sakovich, 2002).
In South African viticultural regions, C. aspersum feeds essentially on the developing foliar buds and young leaves of the vines. In kiwifruit vineyards (California, New Zealand), damage occurs on the flowers, not the fully developed fruit, since snails consume only the sepal tissue around the receptacle area. Damage to the sepals can be detrimental by increasing the development of the fungus Botrytis cinerea during cold storage of fruits, and moreover, the slime trail mucus stimulates germination of B. cinerea conidia (Michailides and Elmer, 2000).

Impact

C. aspersum, the common garden snail, is represented by several forms that are highly differentiated genetically. Only one lineage, the western one, is considered to be invasive in regions where it has been introduced recently (since the sixteenth century) either accidentally or intentionally (e.g. North and South America, South Africa, Oceania). It was in California, USA, where it was introduced in the 1850s, that it was first treated (1931) as a regulated pest. Its success in colonizing new areas after introduction and establishment may be due to: (i) large phenotypic variation in combinations of life-history traits, especially reflecting a high degree of plasticity (e.g. trade-off of egg weight/egg number), and (ii) great resistance against natural enemies. Also, genetic data indicate that C. aspersum is capable of establishing even after a severe genetic bottleneck.

Hosts

C. aspersum is a polyphagous grazer with a large diet spectrum. In its natural habitat, it feeds on wild plants such as Urtica dioica or Hedera helix, which are also used for shelter. In human-disturbed habitats, a wide range of crops and ornamental plants are reported as hosts: these include vegetables, cereals, flowers and shrubs (Godan, 1983;Dekle and Fasulo, 2001). In particular, it causes serious damage in citrus groves and vineyards. It will feed on both living and dead or senescent plant material. The Host Plants/Plants Affected table does not cover all plants that C. aspersum will feed on, as the list is so extensive but aims to provide an insight to the well-known species affected. The categorization as 'Main', 'Other' or 'Wild host' is also subjective and should not be considered definitive.

Biological Control
<br>As terrestrial molluscs have many natural enemies, there has been strong interest in the biological control of C. aspersum using other, predatory snails (e.g. Fisher and Orth, 1985). However, as most of these predatory snails are not host-specific, they are not appropriate to use in control programmes in which effects on non-target species are of concern (Cowie, 2001: Barker and Watts, 2002).<br>There have been several attempts to develop biological control of C. aspersum in California, South Africa and New Zealand, which began with the introduction of predaceous snails (Euglandina rosea, Gonaxis sp.) and beetles during the 1950s and early 1960s (for more information see Fisher and Orth, 1985;Barker and Efford, 2004). These efforts were largely unsuccessful, although one staphylinid beetle (Staphylinus (Ocypus) olens) showed potential;however, the use of this species as a biological control in orchards has not been actively pursued (Sakovich, 2002). In 1966, however, another (opportunistic) predaceous snail, the decollate snail Rumina decollata (of European origin) was found to have invaded California (see Pictures). Experimental releases of R. decollata in southern California citrus orchards were begun in 1975 and, in most cases, resulted in complete control (displacement) of C. aspersum (Fisher and Orth, 1985). Rumina decollata is now used to control C. aspersum in some 20,000 ha of citrus in southern California, but is currently permitted only in certain Californian counties (Dreistadt et al., 2004). As this predatory snail consumes young to half-grown snails, control is achieved only in 4-6 years. Sakovich (2002) recommended first using molluscicidal baits to reduce the population, and then combining skirt-pruning and copper barriers with introduction of R. decollata. Once control by R. decollata is achieved, maintenance of copper barriers can cease, R. decollata can be harvested and transferred to new areas. However, Cowie (2001) expressed concern regarding both the effectiveness of R. decollata in control of C. aspersum, its potential impacts on native (even endangered) species and its potential as a garden plant pest.<br>A study by Altieri et al. (1982) was carried out in a daisy field in northern California to determine the effectiveness of the indigenous coleopterous predator Scaphinotus striatopunctatus in the biological control of C. aspersum. Release of the predator in the field under light metal sheets, together with colonization by garter snakes (Thamnophis elegans) from an adjacent field, resulted in a significant reduction in snail populations.<br>In South Africa, the native predacious gastropod Natalina cafra was investigated as a potential biological control agent against C. aspersum, with special attention to the possibility of establishing a viable population of the natural enemy in captivity (Joubert, 1993), but this approach seems not to have been implemented.<br>Research by the Entomology Division of the Plant Protection Department, Cukurova University, Turkey, on the importation of predators and parasitoids as biological control agents (mainly for citrus pests) included the coccinellid Hippodamia convergens as a potential predator of C. aspersum (Uygun and Sekeroglu, 1987).<br>Ducks, chickens or guinea fowl can provide long-term control in citrus orchards and vineyards, if an appropriate breed is chosen and properly cared for. Growers take the animals each morning into the orchard for as little as half an hour to scavenge for food. This solution can be very effective but involves extra labour in managing the animals and protecting them from predators (Sakovich, 2002;Davis et al., 2004).

Source: cabi.org
Description

The following description is from the Flora of China Editorial Committee (2016)

Impact

Erechtites hieraciifolius is a fast-growing, annual herb that is native to North, Central and South America and the Caribbean. It is recorded as an environmental and agricultural weed in areas both within and outside its native distribution. Mature plants can produce large amounts of wind-dispersed seed, facilitating the colonisation of new areas. It is adapted to grow in a wide range of disturbed anthropogenic habitats and can outcompete other species to form dense populations. It may also spread as a seed contaminant of crops. Currently, it is listed as invasive in Hong Kong, Hawaii, the Galapagos Islands, French Polynesia, Palau, US Minor Outlying Islands, New Zealand and Hungary. It is also considered a potential weed in Australia, where it is under quarantine.

Hosts

E. hieraciifolius has been listed as a weed of the following crops: oat (Avena sativa), barley (Hordeum vulgare), maize (Zea mays), strawberry (Fragaria ananassa), onion (Allium cepa), carrot (Daucus carota), cranberry (Vaccinium macrocarpon), blueberry (Vaccinium spp.) and sugarcane (Saccharum officinarum);it is also a weed of fodder crops (e.g. Medicago sativa) and of mixed pastures (Darbyshire et al., 2012).


Source: cabi.org
Description

P. paniculatum is a perennial grass;culms densely tufted, 0.3 to more than 2 m high, coarse, leafy, erect or ascending, sometimes decumbent at the base and rooting at the lower nodes, finally branching, the nodes glabrous to conspicuously bearded with stiff ascending hairs;sheaths mostly longer than the internodes, keeled, sometimes only on the collar and along the margins, colored orange-brown on the inner surface;ligule 1-3 mm long;blades 9-50 cm long, 6-25 mm wide, usually rounded at the base, densely hispid on both surfaces to nearly glabrous, with a tuft of long hairs on each side at the base, the margins scabrous;inflorescence 5-30 cm long, composed of 7-60 approximate, solitary or somewhat fascicled racemes, the lower ones 4-12 cm long, ascending or arcuate- spreading;spikelets paired, 1.3-1.5 mm long, densely crowded, the glume and sterile lemma equal, barely covering the fruit, softly pubescent, the sterile lemma woolly pubescent only on the margins;fruit about as large as the spikelet, smooth and shining (Flora of Panama, 2016).

Impact

P. paniculatum is a fast-growing grass sometimes used as an “auxiliary forage” crop (PROTA, 2016). Within and outside its native distribution, P. paniculatum behaves as an environmental and agricultural weed and can be found growing along roadsides, in disturbed places, moist shrublands, low open grounds, brushy slopes, forests, open ground, croplands and pastures (Zuloaga et al., 2003;Más and Garcia-Molinari, 2006;Más and Lugo, 2013;AusGrass2, 2016). Plants produce numerous seeds with germination rates higher than 85% (range: 86.5 to 99%, PROTA, 2016). Currently, this species is listed as invasive on Hawaii, Cuba, Trinidad and Tobago, Samoa, Northern Marianas Islands, Micronesia, Fiji, French Polynesia, New Caledonia, Niue, Palau and the Solomon Islands (Wagner et al., 1999;Oviedo Prieto et al., 2012;PIER, 2016;Trinidad and Tobago Biodiversity, 2016).


Source: cabi.org
Description

A. biennis is an annual or biennial herbaceous plant. Stems are 1–3 m tall (although flowering plants may be as little as a few cm tall), erect and more or less spike-like, simple or somewhat branching at the base from a firm taproot. The stems are glabrous throughout, striate and often reddish.The leaves are alternate, glabrous, sessile, pinnatifid into narrow lobes with the lower leaf segments also pinnatifid, lobes of all but the uppermost toothed. Inflorescence a compound spike-like panicle, leafy throughout, with dense clusters of more or less globose capitula (flower heads) which are nearly sessile along short branches arising from upper leaf axils. Each flower head consists of a hemispheric involucre 2–3 cm long, made of 8–14 glabrous bracts. There are 6–22 or more outer pistillate (ray) florets, and 15–40 central bisexual disc florets. Corollas very small, pale yellow to whitish, with scattered stalked glands;corollas of the outer ray flowers about 1 mm long, somewhat tubular;those of the disk flowers bell-shaped, 1–2 mm long, with five triangular teeth. Cypselae (seeds) obovoid to ellipsoid, glabrous, lacking a pappus (bristles), very small (0.2–0.9 mm long), longitudinally 4-5 nerved and light brown.

Impact


The large seed production, small sticky seeds and adaptation to disturbed habitats facilitated the early and rapid spread of A. biennis beyond its natural range in North America, along transportation corridors and in association with human activities. In recent decades it has become invasive in some agricultural areas in North America. The increasing prevalence of A. biennis in agricultural lands seems to be associated with several factors, including: a shift to annual growth habit;increasing adoption of reduced tillage systems;crop diversification;and, a tolerance to several classes of herbicides. In Europe, the plant has become a local weed, but has not yet been reported as invasive in crops. However, increased frequency has been observed in some countries and changes in land use and agricultural practices suggest the potential for emerging problems in Europe in the future.


Source: cabi.org
Host plants Coniothyrium glycines
Description

C. glycines produces monophialidic, ampulliform, conidiogenous cells formed from the inner cells of the pycnidial wall (Hartman and Sinclair, 1988). Pycnidiospores are ellipsoidal, one-celled, and 4-8 µm long by 1-3 µm wide. Sclerotia range in size from 96 to 357 µm in diameter, and are mostly spherical, dark brown to black, and covered with setae, 5 to 36 µm long. It is interesting to note that when the name changed from Dactuliochaeta glycines to Phoma glycinicola (de Gruyter and Boerema, 2002) and then to C. glycines (de Gruyter et al., 2013), there was no mention of the importance of the sclerotia produced by the fungus. It appears that species of Phoma and Coniothyrium do not produce similar sclerotia to C. glycines, which makes this fungus unique in its biology. The uniqueness of the sclerotia may provide a characteristic that can be used for field diagnosis as they can be seen clearly with the aid of a hand lens.

Recognition

There are limited or no exports of soyabean from countries in sub-Saharan Africa to countries outside of Africa, and there have been no documented cases of movement of the pathogen from countries with this disease. Any shipment of soyabean seeds from infected countries would need to enter the USA through a seed permit process managed by USDA APHIS. Similar permitting processes are presumably in place in other countries, which would be the first step in excluding the pathogen from establishment in countries without the disease.

Symptons

C. glycines produces similar symptoms on soyabean and Neonotonia wightii. Initial symptoms can occur at the seedlings stage on unifoliolate leaves. Early lesion development is often associated with primary veins (see Pictures). Under conditions conducive for disease development, symptoms appear over time from the lower to the upper trifoliolate leaves as dark red blotches on the upper surfaces and similar reddish-brown blotches with dark borders on the lower surface s. The fungus also causes lesions on petioles, stems and pods (see Pictures).

Impact

Red leaf blotch affects soyabean in central and southern Africa. The disease and the causal fungus (Coniothyrium glycines) were first reported in Ethiopia in 1957. C. glycines is native to Africa, living on the native legume, Neonotonia wightii, and perhaps other native or non-native legumes. The jump of the pathogen to soyabean occurred as early as 1957 and reports of the occurrence of red leaf blotch have increased along with soyabean production in Africa. The disease is currently a serious threat to soyabean production in sub-Saharan African countries with losses of up to 70% reported. C. glycines is considered a threat to soyabean-producing countries such as Brazil and the USA. The pathogen is not known to be disseminated by seed or wind. Infection is thought to occur via rainsplash of soilborne inoculum onto the leaves of soyabean plants. Symptoms include characteristic dark red spots on the upper leaf surface and reddish-brown lesions with dark borders on the lower surface. Premature leaf drop may occur in heavy disease conditions, releasing sclerotia back into the soil. The disease is favoured by wet, humid conditions.

Hosts

Soyabean is the only known crop host under field conditions. The only other host found to be naturally infected is Neonotonia wightii. The experimental host range through inoculation includes the crops cowpea, lima bean, pigeon pea and winter vetch, and non-crops Glycine argyrea, G. canescens, G. clandestina, G. cyrtoloba, G. falcata, G. latrobeana, G. soja [ G. max subsp. soja ], G. tabacina, G. tomentella, N. wightii and Pueraria lobata [ Pueraria montana var. lobata ] (Hartman and Sinclair, 1992).


Source: cabi.org
Description

Herbaceous, twining or creeping vine, attaining up to 6 m in length. Stems cylindrical, glandular- pubescent. Leaves alternate, 5-palmately compound;leaflets 1.5-7.5 x 0.7-3.5 cm, elliptical, ovate or ovate-lanceolate, the apex obtuse, the base acute or decurrent, the margins entire, undulate or dentate, glabrate or glandular-pubescent on both surfaces. Flowers in simple or double dichasial cymes;peduncles longer than the petioles;bracts persistent, linear to subulate;sepals subequal or unequal, 1-1.5 cm long, ovate to ovate-lanceolate, acuminate at the apex, glandular-pubescent;corolla funnel-shaped, white or sometimes pink, with or without a purple centre, 1.5-3 cm x 3-4 cm;stamens 5, white, sometimes with lilac anthers;stigma bilobed, white. Fruit capsular, 4-valvate, globose, 6-8 mm in diameter, light brown, glabrous, surrounded by the persistent sepals. Seeds 4 per fruit, ellipsoid, 5-6 mm long, dark brown, lanate (Acevedo-Rodríguez, 2005;Austin et al., 2012).

Impact

Merremia cissoides is a climbing weed native to tropical America that has been introduced to several Old World countries, presumably as an ornamental. It typically grows in disturbed areas and has been reported as a weed of several crops within its native range. However, it is not as widespread and common as other weedy species of Merremia. In several countries outside its native range, its occurrence has only been documented from one or few herbarium specimens. Nonetheless, the species is considered to be increasingly naturalized in the Old World tropics. It is invasive in Florida (USA) and Cuba.

Hosts

The species has been reported as a weed of sugarcane fields in Brazil (Perim et al., 2009;Correia and Kronka Júnior, 2010) and has also been reported in maize (Tavella et al., 2015), soybean (Timossi and Durigan, 2006), eucalyptus (Carbonari et al., 2010) and coffee plantations (Gavilanes et al., 1988).


Source: cabi.org
Description

D. caricosum is a perennial, stoloniferous grass. Culms tufted at nodes of stolons, geniculately ascending, 30–60 cm tall, nodes glabrous or pubescent. Leaf sheaths compressed, keeled, shorter than internodes;leaf blades flat, 15–20 cm × 2.5–5 mm, glabrous or with a few hairs at base, margins smooth or scabrid, apex acuminate;ligule less than 1 mm, margin ciliate. Inflorescence terminal;peduncle glabrous;racemes (1–)2–4, 2.5–5 cm, with 1–3 pairs of homogamous spikelets. Sessile spikelet 3–3.5 mm;lower glume obovate-elliptic or obovate-oblong, papery, 8–12-veined, glabrous or often sparsely hirsute on lower back, slightly glossy, margins shortly ciliate, keels winged, apex rounded;upper glume ciliate above middle, apex obtuse;awn 1.5–2.5 cm, weakly geniculate. Caryopsis obovate-oblong. Pedicelled spikelet many-veined, resembling sessile (Flora of China Editorial Committee, 2015).

Impact

D. caricosum has been intentionally introduced as a perennial grazing pasture with excellent ground cover. Now, it can be found widely naturalized in tropical and subtropical regions (Cook et al., 2005;FAO, 2015). It has escaped from cultivation and has become a weed and invasive grass in Cuba, Guam, New Caledonia, and Fiji (MacKee, 1994;Oviedo Prieto et al. (2012);PIER, 2015). In Cuba, it is widespread across the islands. In Fiji, it covers large areas being very common especially in the dry zones, in pastures, canefields, waste places, and along roadsides (Smith, 1979). D. caricosum is a fast-growing gregarious grass that competes aggressively with other plants including other weeds (Cook et al., 2005).

Hosts

D. caricosum is a common weed with negative impact in pastures and sugarcane fields (Smith, 1979).


Source: cabi.org
Description

M. eruciformis is an annual terrestrial herb growing up to 45 cm tall and forming dense clusters of 10-60 cm long reclining and slender stems, with softly hairy culms rooting at the lower nodes. Stem internodes are hollow.

Impact

Moorochlora eruciformis is an annual herb, fodder crop and common agricultural weed, native to Africa, Asia and the Mediterranean;it has also been introduced to the Americas and Oceania. Crop seed contamination is a possible pathway for dispersal of this species. It is reported as invasive in Cuba, Spain and Australia as well as islands in Oceania. Despite this, there is limited information available about the economic and environmental impacts of this species or its dispersal potential.

Hosts

It is a common weed species in cultivated fields, particularly associated with maize, sugarcane and coffee crops (Holzner and Numata, 1982;Blanca et al., 2009;Afridi et al., 2015).


Source: cabi.org
Description


Live adult females are oval, grey, and coated with white mealy wax which forms small tufts (Beardsley 1959). They are 1.5 mm long and 1.0 mm wide. Authoritative identification requires slide-mounted adult females under a compound light microscope. See Beardsley (1959) for a detailed description of the D. neobrevipes.

Recognition

D. neobrevipes crawlers (first-instar nymphs) can be detected in the field using blue sticky traps. Jahn and Beardsley (2000) found blue sticky traps better for trapping D. neobrevipes than yellow sticky traps, which attract high numbers of other insects, such as flies.
D. neobrevipes is only found on the aerial parts of the plant (Beardsley 1960) and is usually seen on the surface, but can feed deep in the leaf axils or within the blossom cups. Therefore, a plant may need to be dissected in order to find all of the mealybugs on it (Jahn et al., 2003).

Symptons

D. neobrevipes is usually found near the top of the host plant and feeds by sucking phloem sap from the plant tissue. This may cause local lesions to form at the site of feeding on some hosts. These lesions are bizonate, with a dark green centre surrounded by a lighter green area (Dasgupta, 1988). D. neobrevipes also affects the plant’s photosyntheitic ability by excreting sugary honeydew that fouls plant surfaces, forming a medium for the growth of sooty mould, which blocks sunlight and air from reaching the leaves, impairing photosynthesis (Tabata and Ichiki, 2015).
The main damage that pineapple mealybugs such as D. neobrevipes cause is as a result of their role as a vector of pineapple wilt. This devastating disease is caused by Pineapple mealybug wilt associated virus-2 (PMWaV-2), a mealybug-transmitted ampelovirus (Subere et al., 2011). There are two types of wilt, quick wilt and slow wilt. Quick wilt, also known as mealybug wilt, develops around 2 months after a short attack by a large colony of mealybugs, whereas slow wilt is caused by many mealybugs feeding on the plant tissue over many months (Jahn et al., 2003). Slow wilt causes the inner leaves to turn dry and brown, and outer leaves to lose their turgidity and droop (Jahn et al., 2003). Unlike slow wilt, quick wilt causes leaves to turn a light-green to yellow-pink colour in plants younger than 6 months. In older plants, quick wilt causes leaves to droop, turn pink and dry out (Carter, 1932).
Both types of wilt cause leaves to droop and dry out. They also both affect the fruit yield of the plant, especially if symptoms are seen early in the season. Affected plants either produce smaller fruit or produce no fruit at all. Pineapple wilt may also result in the invasion of saprophytic organisms, which leads to collapse of the roots (Kessing and Mau, 1992). Ultimately, plants may die as a result of infection by pineapple wilt transmitted by D. neobrevipes.
D. neobrevipes also causes green spot disease of pineapple, which is characterized by galls on leaves caused by a reaction between the plant and a secretion from the mealybugs.

Impact

Dysmicoccus neobrevipes is a mealybug with a pantropical distribution. It is an economically important pest that can feed on and damage dozens of hosts, principally pineapple and the banana Musa × paradisiaca. The main damage caused by D. neobrevipes is due to its role as a vector of mealybug wilt (Plant Health Australia, 2013). Qin et al. (2010) considered it a dangerous alien species with a high risk of invasion in China. Although D. neobrevipes can colonize without the help of associated caretaker ants, most commonly Pheidole and Solenopsis, the ants’ presence can help them to invade new areas by providing shelter and protecting them from natural enemies and adverse weather conditions.

Biological Control
D. neobrevipes has a range of natural enemies that, in the absence of caretaker ants, can effectively control populations of the mealybug. New predators can be introduced to an area in order to control the mealybugs, but without first controlling ant populations, these introductions will not be effective (Rohrbach et al. 1988).

Source: cabi.org
Description

The following description is adapted from Austin and Staples (1991) and Acevedo-Rodríguez (2005)

Impact

Turbina corymbosa is a perennial, neotropical vine that has been introduced as an ornamental in the Canary Islands, Australia and several Old World countries. It is a serious problem in northern Queensland, Australia, where it is invading rainforest ecosystems and displacing native vines and shrubs, and is sometimes considered an environmental and agricultural weed elsewhere.

Hosts

It is reported as a weed of bean (Phaseolus vulgaris) and orange (Citrus sinensis) crops in Cuba (Sampedro Romero et al., 2002;Castellón-Estévez et al., 2011).


Source: cabi.org
Description

T. alata is an herbaceous vine, creeping or climbing, twining, 2-3 m in length. Stems cylindrical, slender, puberulous. Leaves opposite;blades 4.5-10.5 × 3.2-6 cm, ovate, lobed, chartaceous, the apex acute, the base subcordiform;upper surface dark green, dull, pubescent;lower surface pale green, dull, with prominent venation;petioles 4-8 cm long, winged, pubescent. Flowers axillary, solitary;pedicels pubescent, 4-5 cm long;bracts green, ovate, pubescent, 1.5 cm long, covering the calyx and the corolla tube. Calyx yellowish green, with 12 filiform lobes, approximately 4 mm long;corolla orange, pale yellow, or less frequently whitish, infundibuliform, with 5 lobes, the tube approximately 2.5 cm long, narrow at the base, dark violet inside, the lobes approximately 2.5 cm long with the apex truncate, the limb approximately 5 cm in diameter;stamens with glandular hairs on the basal portion. Capsules approximately 4 mm long, depressed-globose to 4-lobed at the base, the upper half in the form of a beak, dehiscent by two valves;seeds 2 or 4, 1.2-1.5 mm long, semicircular, reticulate (Acevedo-Rodríguez, 2005). Several cultivars have been developed, including some with white, yellow, and even pinkish-coloured flowers (Queensland Department of Primary Industries and Fisheries, 2011).

Impact

T. alata is an herbaceous vine, often cultivated as an ornamental, which has escaped and naturalized mostly in disturbed areas in tropical, subtropical and warmer temperate regions of the world (Starr et al., 2003;Meyer and Lavergne, 2004;Queensland Department of Primary Industries and Fisheries, 2011). It is a fast-growing vine with the capability of reproducing sexually by seeds and vegetatively by cuttings, fragments of stems and roots (Starr et al., 2003;Vibrans, 2009). Once established, it completely smothers native vegetation by killing host-trees, out-competing understory plants, and negatively affecting the germination and establishment of seedlings of native species (Starr et al., 2003;Meyer and Lavergne, 2004). T. alata is included in the Global Compendium of Weeds (Randall, 2012) and it is also considered an aggressive invasive plant in Australia, Japan, Singapore, Costa Rica, Cuba, Puerto Rico, Brazil, Colombia, Paraguay, and numerous islands in the Pacific including Hawaii and French Polynesia.

Hosts

T. alata is considered a weed affecting mostly plantation crops such as Citrus, coffee, mango, and banana plantations (Vibrans, 2009).


Source: cabi.org
Description

Adapted primarily from Keil and Ochsmann (2006) and DiTomaso and Healy (2007)

Impact

C. melitensis is native to northern Africa and southern Europe in the western Mediterranean region, and has successfully invaded similar climates in the USA, New Zealand, Australia and South America. In favourable habitats it can form dense stands that replace native and desirable vegetation. It is commonly less aggressive than Centaurea solstitialis and in some areas grows as a minor forb in annual grasslands. C. melitensis usually invades open, disturbed sites and is often spread by humans and livestock and by transportation of contaminated soil, crop seed or hay (DiTomaso and Healy, 2007).

Biological Control
A small beetle (Lasioderma haemorrhoidale) that feeds in the capitula of C. melitensis was unintentionally introduced in California from the Mediterranean region, but has had little impact on controlling C. melitensis populations (DiTomaso and Healy, 2007). It is a generalist seed feeder that also attacks C. solstitialis, C. sulphurea and Carduus pycnocephalus. Two other agents introduced for C. solstitialis, Chaetorellia succinea and Eustenopus villosus, also utilize C. melitensis, but to a lesser extent (DiTomaso and Healey, 2007). In host specificity tests, there was significant larval development by the Eurasian weevil Ceratapion basicorne on C. melitensis (Smith, 2007).

Source: cabi.org
Description


The following description is taken from Flora of China Editorial Committee (2015):
Annual grass, culms tufted, erect or geniculately ascending, slightly flattened, 15–100 cm tall. Basal leaf sheaths strongly keeled, glabrous;leaf blades flat or folded, 5–30 cm, 2–7 mm wide, glabrous, adaxial surface scabrous, apex acuminate;ligule 0.5–1 mm, glabrous or ciliate. Racemes digitate, 5–12, erect or slightly slanting, 2–10 cm, silky, pale brown or tinged pink or purple;rachis scabrous or hispid. Spikelets with 2 or 3 florets, 2-awned;lower glume 1.8–2.2 mm;upper glume 3–4 mm, acuminate;lemma of fertile floret obovate-lanceolate in side view, 2.8–3.5 mm, keel gibbous, conspicuously bearded on upper margins with a spreading tuft of 2.5–3.5 mm silky hairs, margins, keel and flanks silky-ciliate or glabrous;awn 5–15 mm;second floret sterile, oblong, glabrous, awn 4–10 mm;third floret occasionally present, reduced to a small clavate scale, awnless.

Impact

Chloris virgata is a widespread and very variable weedy annual grass (Flora of China Editorial Committee, 2015). This species is a particularly aggressive invader of bare areas and degraded or disturbed native vegetation, and it has the potential to out-compete native vegetation in these habitats (Smith, 2002;Oviedo Prieto et al., 2012;Weeds of Australia, 2015). This weedy grass spreads from cultivation, pastures, gardens, disturbed areas and roadsides to nearby disturbed forest, creeks and riversides, native grasslands and coastal habitats such as coastal forests and sand dunes (Weeds of Australia, 2015;FAO, 2015;PIER, 2015). It also grows as a weed in agricultural lands (Vibrans, 2009). Currently, this species is regarded as an invasive and environmental weed in northern Australia (i.e., Queensland and the Northern Territory;Weeds of Australia, 2015) and as an invasive grass in Cuba, Palau, New Caledonia, the Galapagos Islands, and Hawaii (Wagner et al., 1999;Charles Darwin Foundation, 2008;Oviedo Prieto et al., 2012;PIER, 2015).

Hosts

C. virgata is a common weed in alfalfa (Medicago sativa) fields of the southwestern USA (Barkworth, 2003) and maize and sorghum plantations in Mexico (Vibrans, 2009).


Source: cabi.org
Description

P. chinensis is a perennial herb. Rhizomes stout. Stems erect, 70-100 cm tall, ligneous at base, much branched, striate, glabrous or retrorsely hispid. Petiole 1-2 cm, usually auriculate at base, upper leaves subsessile;leaf blade ovate, elliptic, or lanceolate, 4-16 × 1.5-8 cm, both surfaces glabrous or hispid, abaxially sometimes pubescent along veins, base truncate or broadly cordate, margin entire, apex shortly acuminate;ocrea tubular, 1.5-2.5 cm, membranous, glabrous, much veined, apex oblique, not ciliate. Inflorescence terminal or axillary, capitate, 3-5 mm, usually several capitula aggregated and panicle-like;peduncle densely glandular hairy;bracts broadly ovate, each 1-3-flowered. Perianth white or pinkish, 5-parted;tepals ovate, accrescent in fruit, becoming blue-black, fleshy. Stamens 8, included. Styles 3, connate to below middle. Achenes included in persistent perianth, black, opaque, broadly ovoid, trigonous, 3-4 mm (Flora of China Editorial Committee, 2014).

Impact

P. chinensis is closely related to other important invasive Persicaria species such as P. orientalis, P. capitata, and P. perfoliata, all species included in the Global Compendium of Weeds (Randall, 2012). P. chinensis is a fast-growing herb that forms dense mats and tolerates diverse environmental conditions (Galloway and Lepper, 2010). It spreads by seed and by resprouting from broken fragments. Its high growth rates and spread potential provides this species the ability to smother other plants affecting plant community structure and composition (USDA-APHIS, 2012). Biosecurity New Zealand described the species in a risk assessment as “a highly invasive plant that quickly smothers available surfaces including other plants and trees,” and PIER (2014) lists it as invasive in several territories, including Hawaii.

Hosts

P. chinensis is a common weed requiring control in tea plantations where it covers tea bushes and blocks drainage systems (Tjitrosemito and Jaya, 1990).


Source: cabi.org
Host plants Viguiera dentata Long
Description


Erect herbs to about 2 m high, the stems slender, sparsely strigillose or glabrate;lower leaves opposite, the upper alternate, petiolate, the blades ovate to rhombic-ovate or lanceolate, mostly 3-12 cm long, acute to long-acuminate, cuneate or attenuate to the petiole, the margins serrate, serrulate, or subentire, strigillose and usually scabrous above, beneath strigillose to densely soft-pilose;inflorescences pedunculate;heads on pedicels mostly 2-8 cm long, disposed in lax, open, cymose panicles;disc of the head 7-10 mm long, 10-14 mm broad;involucres broadly campanulate, 5-10 mm high;phyllaries 3-seriate, lance-ovate or ovate-oblong to linear or linear-oblong, acute or acuminate, herbaceous, spreading or appressed, hispidulous or densely appressed-pilose;ray flowers 10-12, the ligules yellow, 7-15 mm long;disc corollas yellow, more or less hirtellous, 3-4 mm long;achenes obovate-oblong, black or mottled, appressed-pubescent, 3-4 mm long;pappus a crown of fimbriate squamellae less than 1 mm long and 2 slender, unequal awns, 2.2- 2.8 mm long (Nash, 1976).

Impact

V. dentata is an erect herb listed as an invasive species only in Cuba (Oviedo Prieto et al., 2012). On this island, the species grows as an invasive weed in cultivated plots as well as in disturbed sites and ruderal areas. V. dentata also grows as a weed in ruderal areas and thickets within its native distribution range of Mexico and the USA (Vibrans, 2009;Flora of North America Editorial Committee, 2014;USDA-NRCS, 2014).


Source: cabi.org
Host plants Verbena rigida Long
Description

V. rigida grows as an herbaceous perennial plant 50-60 cm in height (ISSG, 2015). It can form dense stands via rhizomes and stolons (Munir, 2002). Leaves are arranged opposite to subopposite along the square stems and leaves clasp the stem (Tveten and Tveten, 2010;ISSG, 2015). The stiff, dark green leaves are oblong in shape, 5-10 cm long, with pointed tips and coarsely serrated edges (ISSG, 2015). Leaves and stems are covered in rough hairs (Tveten and Tveten, 2010). Cylindrical spikes of flowers forming spreading clusters are held at the ends of stems. Each flower calyx is 3-3.5 mm long and the corolla-tube is 5-10(-12) mm long (ISSG, 2015). Flowers are purple in colour and fragrant. Dry fruits separate into four, one-seeded parts. Each seed is about 2 mm long (ISSG, 2015).

Impact

V. rigida is an herbaceous perennial planted as a fast spreading groundcover (Royal Horticultural Society, 2015) and is listed as weedy in many countries (Randall, 2012). It is principally found in disturbed areas but can spread into grasslands and forests and is a weed of cotton fields (ISSG, 2015). However, there is little information on the species impact in agricultural or natural ecosystems. It spreads via rhizomes and seeds (ISSG, 2015), but the extent of dispersal by seed and whether the plant has a seedbank is unknown.

Hosts

V. rigida is a weed in pastures and cotton fields (Munir, 2002) and turf grass (Georgia Turf, 2015) but appears to be a relatively minor weed. Where a weed of cotton fields in Australia (Johnson and Hazlewood, 2002) no information was available on the magnitude of effect or what crop stage is affected. It is considered a weed in cultivation of bald cypress in Florida (Osiecka and Minogue, 2012).


Source: cabi.org
Description

F. gallica is a densely hairy and greyish erect annual, up to 33(50) cm high, with alternate leaves;capitula in clusters, surrounded by linear to linear-lanceolate involucral leaves longer than the capitula.

Impact

Filago gallica is an annual plant native to Europe, Macaronesian Islands, northern Africa and southwestern Asia. It was introduced to North America (USA, Mexico), South America (Chile), India, Australia and New Zealand, where it has naturalized. F. gallica was listed as one of the most common plants of Mediterranean origin invasive in Californian rangelands by Houérou (1991), but currently there is little information indicating its invasive behaviour. It is not recorded as a noxious or (declared) weed in its introduced range of Australia, but F. gallica can behave as an agricultural or environmental weed (Randall, 2007).

Hosts


Within its native range of distribution F. gallica can be an agricultural weed (HEAR, 2015, HYPPA, 2015). F. gallica is an occasional weed of cereal crops, vineyards, olive groves and stone fruit orchards in Europe (France, Portugal and Spain) (Carretero, 2004;HYPPA, 2015).


Source: cabi.org
Host plants Cenchrus biflorus Long
Description

C. biflorus is a loosely tufted, annual grass, with ascending stems (culms) up to 1 m tall. Leaves alternate, simple and entire;ligule a line of hairs;blade linear, flat, 2–25(–35) cm × 2–7(–10) mm, apex filiform. Inflorescence a spike-like panicle 2–15 cm × 9–12 mm, with 1–3 spikelets enclosed by an involucre of prickly bristles;rachis angular, sinuous;involucre ovoid, 4–11 mm long with numerous spines, inner spines erect, fused at base, retrorsely hairy on the pungent, recurving apex, outer spines shorter, spreading. Spikelet lanceolate 3.5–6 mm long, acute, consisting of two glumes and usually two florets;glumes shorter than spikelet;lower floret male or sterile, its lemma as long as spikelet, membranous, upper floret bisexual, its lemma as long as spikelet, thinly leathery;stamens three, ovary superior, glabrous, with two hairy stigmas. Fruit a dorsally compressed caryopsis (grain), 2–2.5 mm × 1.5–2 mm (PROTA, 2015).

Impact

C. biflorus is an annual grass native throughout tropical Africa into Pakistan and India. It has been introduced outside of its native range into southern Africa, North America and Australia. C. biflorus is used as a forage and famine crop but more recently it has been recognised as an invasive species. The retrorsely barbed bristles are readily spread in animal fur and can seriously reduce the value of animal hides, while the barbs can damage the mouths of grazing animals. In addition to this, it is possible for this species to dominate disturbed areas and suppress the growth of native biodiversity. C. biflorus is reported as an agricultural weed in a number of countries including Niger, Nigeria, Saudi Arabia and Senegal.

Hosts

C. biflorus occurs as a weed in a wide range of crops, including Pennisetum glaucum (pearl millet) (Munde et al., 2012), Hibiscus sabdariffa (roselle) (El-Naim and Ahmed, 2010) and species of Sesamum indicum (sesame) (Chandawat, 2004).


Source: cabi.org
Description


The morphology of the adult was addressed by Kumata (1963) and Kumata et al. (1983). The caterpillar chaetotaxy was described by Kumata (1993) and the morphology of the pupa was described by Gregor and Patocka (2001). The morphology of all the stages, including the larval chaetotaxy was studied by Sefrová (2002).
Egg
The egg is slightly elongated, ellipsoidal, and has a delicate pitting on the chorion surface. It is 0.32-0.37 mm by 0.23-0.27 mm. It is greenish-ochreous, which corresponds to the undersides of the leaves on the host plant.
Larva
The larval morphology corresponds to the morphology of other Phyllonorycter larvae. The larva is whitish-ochreous and is 4.0-5.6 mm long in the final instar. There are five larval instars. The first three instars are flat with reduced mouthparts and legs (sometimes called sap-feeding instars e.g. Kumata, 1978). The triangulate head capsule shows prognathy without spinneret, labial and maxillary palpi. There is a close group of stemmata on the head near the antennal base of these instars. The triangular mandibles with three curved cusps are moved horizontally between the huge flat labrum and the labium. The thoracic segments are strikingly dilated (especially in the first instar) compared with the abdominal segments. This characteristic decreases with the next instars. The final two instars (tissue-feeding instars) show the morphology of exophagous caterpillars. Their heads are more globular, semiprognathous and have complete mouthparts. The mandibles are more or less rectangular with five cusps on the frontal edge and they move vertically. The stemmata form a quadrangle. The thoracic legs, abdominal prolegs (on the third to fifth segments) and anal prolegs are normally shaped. The 23-38 claws of each proleg are positioned in multiple, usually irregular circles. The individual instars can be primarily distinguished according to the width of the head capsule: I: 0.14-0.16 mm;II: 0.18-0.21 mm;III: 0.25-0.28 mm;IV: 0.25-0.30 mm;and V: 0.31-0.40 mm.
Pupa
The pupa is light brown to brownish-black and 3.2-4.0 mm long. Its frontal process is short and broad. It is in the shape of an equilateral triangle with distinct surface sculpture. Abdominal segments two to eight bear two pairs of rigid setae and their dorsal parts are covered with coarse thorns. The male genitalia only slightly protrude. The tenth abdominal segment is long, with a broad anal field. This has an elongate cremaster, which is round in ventral view, and elongate and strongly constricted in lateral view, with one pair of small hooked thorns at the end.
Adult
The wingspan is 6.3-8.3 mm. The adult exhibits distinct seasonal dimorphism. The aestival form has a whiteish-ochreous frons and labial palpus. The hair tuft on the head is ochreous with individual white scales. The antennae are greyish-white with black circles. The thorax is golden-ochreous, with three white lines. The forewing is golden-ochreous, with a long and narrow basal streak (occasionally indistinct), lacking a dark margin, or with individual dark scales only on its fore margin. The first (basal) transversal streaks are narrow and slope outwards. The dorsal streak is distinctly longer than the costal streak. The other three costal streaks are located close to each other before the apex. The second dorsal streak, which is before the tornus, occasionally fuses with a light tornal spot. The basal margins of all the streaks are more or less bordered with black scales. A distinct line of black scales divides the yellowish-white cilia. The hind wings and their cilia are pale grey.
The winter form (differences only) has a hair tuft on the head that is greyish-black or black with individual white scales, and is entirely white. The thorax is dark brown, and occasionally has white scales and white, indistinct lines. The forewing is grey, greyish-brown or greyish-black, mixed with white and brownish-black scales or spots. The ground colour of the winter form is very variable from pale grey to brownish-black. This striking habitual seasonal difference is possibly due to the fact that the hibernating individuals easily escape the attention of their predators in overwintering shelters. No sexual dimorphism has been observed.


Source: cabi.org
Description

A. atratus puparia are elliptical, black, 1.0-1.1 mm long with a long marginal white wax fringe and dorsal wax filaments that often completely cover the insect. The puparia often occur in dense colonies that smother the underside of the fronds with puparia, wax secretions and honeydew, on which sooty moulds grow.

Recognition


Eggs and larvae of A. atratus occur on the underside of palm fronds, and when abundant they are highly conspicuous due to the flocculent white wax which covers the pupae. Adult whitefly may be found on both upper and lower surfaces of palm fronds. The upper surfaces of infested fronds often exhibit chlorosis or necrosis. Infested palms may also exhibit wilting and a covering of sticky honeydew and associated sooty moulds.
However, field identification of A. atratus is unreliable as there are similar species with black pupae in the genus Aleurotrachelus and other genera such as Aleurotulus, Aleurolobus and Tetraleurodes.

Symptons


The upper surfaces of infested palm fronds often exhibit chlorosis and/or necrosis. The undersurfaces of infested fronds will be covered in dense patches of black puparia covered in conspicuous white wax secretions. The foliage, stems and fruit may be covered with sticky honeydew which serves as a medium for the growth of sooty moulds. Large whitefly infestations may cause wilting and the plant may lose vigour;consequently, there may be a decrease in fruit production.

Impact


The whitefly A. atratus is a highly invasive pest of coconut and ornamental palms (Arecaceae). Before the 1990s this species was only known to feed on coconut from Brazil (Hempel, 1922;Mound and Halsey, 1978), but since 2001 it has been reported widely in the tropics and subtropics on more than a hundred plant species and is known to be invasive in Cape Verde, Comoros, Mauritius, Mozambique and the Seychelles. Mainly thelytokous, it is oligophagous on perennial palms, and has winged adults, all of which allows it to naturalize in new areas after accidental introduction on host plant material. It has also been found on indoor plantings of palms in botanical collections in temperate regions (Malumphy and Tresedar, 2011). The biology, host range and increasing geographical distribution of A. atratus have been studied in detail by Borowiec et al. (2010), and reviewed by Malumphy and Tresedar (2011).

Hosts

A. atratus has been recorded feeding on 114 host plant species belonging to five families. Most (96%) hosts are palms in the family Arecaceae. Coconut is the most commonly reported host. A. atratus is occasionally recorded on non-palm hosts, including two highly important crops, citrus and aubergine. The significance of A. atratus on non-palm hosts, however, is unclear (Malumphy and Tresedar, 2011).

Biological Control
<br>Biological control measures targeted at A. atratus in a glasshouse at a botanical garden in the UK have included introductions of Amblyseius swirskii Athias-Henriot (Mesostigmata: Phytoseiidae), Chilocorus nigritus Fabricius (Coleoptera: Coccinellidae) and Eretmocerus eremicus Rose and Zolnerowich (Hymenoptera: Aphelinidae) to areas of high whitefly infestation. No evidence, however, has been observed of any of these biological control agents being effective against A. atratus.<br>The parasitoid Eretmocerus cocois was found to effectively parasitize populations of A. atratus in Guadeloupe (Neotropics) and in the Indian Ocean islands of Réunion and Mayotte (Delvare et al., 2008), and was introduced to Ngazidja (Comoros Islands) for the biological control of the whitefly by CIRAD and the Agriculture, Fisheries and Environment Research Institute (INRAPE) in the Comoros within the Crop Protection Network for the Indian Ocean (PRPV). The parasitoid proved an effective biocontrol agent of A. atratus (Cave, 2008), and may be introduced to the Seychelles (Hobson, 2012).

Source: cabi.org
Description


Lso is a phloem-limited, Gram-negative, unculturable bacterium that is primarily spread by psyllid insect vectors (Hansen et al., 2008;Munyaneza et al., 2008;Secor et al., 2009;Munyaneza et al., 2010b). This bacterium can also be transmitted from infected to healthy plants through grafting (Crosslin and Munyaneza, 2009;Secor et al., 2009). Lso has also been shown to be transmitted both vertically (transovarially) and horizontially (from feeding on infected plant hosts) in Bactericera cockerelli (Hansen et al., 2008). Lso is closely related to the liberibacters associated with Huanglongbing, or citrus greening, the most destructive disease of citrus in the world (Bové, 2006).

Recognition


The characteristic above-ground plant symptoms of Lso infection in both solanaceous species and carrot resemble those caused by phytoplasmas and spiroplasmas (see Symptoms). Therefore, the confirmation of Lso infection with biological molecular techniques following visual inspection is essential. However, zebra chip symptoms in potato tubers are generally characteristic and could reliably be used to inspect Lso infection in potatoes.

Symptons


Characteristic above-ground plant symptoms of Lso infection in potato, tomato and other solanaceous species resemble those caused by phytoplasmas and include: stunting;erectness of new foliage;chlorosis and purpling of foliage, with basal cupping of leaves;upward rolling of leaves throughout the plant;shortened and thickened terminal internodes resulting in plant rosetting;enlarged nodes, axillary branches or aerial tubers;leaf scorching;disruption of fruit set, and the production of numerous, small, misshapen and poor quality fruits (Munyaneza et al., 2007a,b;Liefting et al., 2009a;Secor et al., 2009;Crosslin et al., 2010;Munyaneza, 2010;2012).
In potato, the below-ground symptoms include collapsed stolons, browning of vascular tissue concomitant with necrotic flecking of internal tissues and streaking of the medullary ray tissues, all of which can affect the entire tuber. Upon frying, these symptoms become more pronounced and chips or fries processed from affected tubers show dark blotches, stripes or streaks, rendering them commercially unacceptable (Munyaneza et al., 2007a,b;2008;Secor et al., 2009;Crosslin et al., 2010;Miles et al., 2010). The symptoms in potato tubers have led to the disease being named ‘zebra chip’ (Munyaneza et al., 2007a,b;Munyaneza, 2012).
Symptoms in carrots infected with Lso resemble those caused by leafhopper-transmitted phytoplasmas and spiroplasmas in carrots (Font et al., 1999;Lee et al., 2006;Cebrián et al., 2010;Munyaneza et al., 2011) and include: leaf curling;yellowish, bronze and purplish discoloration of leaves;stunting of the carrot shoots and roots, and proliferation of secondary roots (Munyaneza et al., 2010a,b;2012a,b;Alfaro-Fernandez et al., 2012a,b).

Impact

Candidatus Liberibacter solanacearum (Lso) is a phloem-limited, Gram-negative, unculturable bacterium that is primarily spread by psyllid insect vectors. It is considered very invasive due to its ability to be transported primarily in infective psyllids (Munyaneza et al., 2007a;2010a,b;2012a,b;Munyaneza, 2012;Alfaro-Fernandez et al., 2012a,b). It has been shown that Lso distribution in the Americas, New Zealand and Europe follows the distribution of its known psyllid vectors (Munyaneza, 2010;2012).

Hosts


Lso primarily infects solanaceous species, including potato, tomato, pepper, eggplant, tobacco, tomatillo, tamarillo and several weeds in the family Solanaceae (Hansen et al., 2008;Liefting et al., 2008a,b;2009a,c;Abad et al., 2009;Crosslin and Munyaneza, 2009;Lin et al., 2009;Munyaneza et al., 2009a,b,c;Secor et al., 2009;Wen et al., 2009;Brown et al., 2010;Crosslin et al., 2010;Munyaneza, 2010;Sengoda et al., 2010;Munyaneza, 2012;Butler and Trumble, 2012;Aguilar et al., 2013a,b;Bextine et al., 2013a,b;Munyaneza et al. 2013a,b;2014a). This liberibacter species is transmitted to solanaceous species by Bactericera cockerelli.
Lso has also been found to infect carrots and celery in Europe, where it is transmitted to carrot by T. apicalis and Bactericera trigonica (Munyaneza et al., 2010a,b;2011;Alfaro-Fernández et al., 2012a,b;EPPO, 2012a;Teresani et al., 2014). It is suspected that Lso is likely to have more insect vectors and host plants than currently known.


Source: cabi.org
Description


Hyphae with frequent nodules, up to 8 µm wide, hyphal swellings in clusters, typically spherical, average 42 µm diameter. Sporangiophores thin (3 µm wide), proliferating through the empty sporangium or occasionally branched. Sporangia broadly ellipsoid to ovoid, 57 x 33 µm (up to 100 x 40 µm), no papilla, slight apical thickening, not shed. Oogonia average 40 µm diameter, wall smooth, becoming yellowish with age. Antheridia amphigynous, 21-23 x 17 µm. A full description is given in Waterhouse & Waterston (1966).

Symptons

P. cinnamomi causes a rot of fine feeder roots, and root cankers in some species, leading to dieback and death of host plants. Other symptoms include wilt, stem cankers (with sudden death of tree), decline in yield, decreased fruit size, gum exudation, collar rot (if infected through grafts near soil level) and heart rot (e.g. pineapple). A symptomless invasion of the sapwood has been reported in some species (Davison, 2011).

Impact

P. cinnamomi is a soilborne pathogen that is now widely established in many parts of the world. Initial long-range spread is likely to have been on infected nursery plants (e.g., Kenerley and Bruck, 1983;Benson and Campbell, 1985;Davison et al., 2006), and still occurs in this way. Additional long-range spread is by movement of soil and gravel infested with chlamydospores (e.g., Batini, 1977;Colquhoun and Petersen, 1994). Short-range spread is also by zoospores in drainage, seepage and irrigation water (Kinal et al., 1993;MacDonald et al., 1994). It has a very wide host range (Zentmyer, 1980) so that, once introduced into an area, it can persist on the roots of many different plants without necessarily causing symptoms on the foliage. It is a major pathogen of horticultural crops, in forestry and in natural vegetation, especially in southern Australia (Natural Resource Management Western Australia, 2013 - see http://www.dieback.net.au/pages/1382/susceptible-species). It is regarded as a key threatening process in the Australian environment (Environment Protection and Biodiversity Conservation Act, 1999), affecting both plant communities by reducing diversity, and the animal communities that depend on them.

Hosts


The host range is very wide and P. cinnamomi is the most widely distributed species of Phytophthora. Zentmyer (1983) stated there were nearly 1000 host species but, as research continues, the Project Dieback website (Natural Resource Management Western Australia, 2013) reports that over 2000 native plants are susceptible to Phytophthora dieback in Western Australia. The principal food crop hosts are avocados (root rot) and pineapples (root and heart rot);it also attacks Castanea, Cinnamomum, conifers, Ericaceae (including Rhododendron), Eucalyptus, Fagus, Juglans, Quercus and many ornamental trees and shrubs. Its recorded host range includes most of the temperate fruit trees, but these are not important hosts in practice. The impact of infection on hosts varies from symptomless infection restricted to root tissue to complete invasion of the root and stem storage tissue causing plant death (Environment Australia, 2001).


Source: cabi.org
Description

The fungus was first described in 2011 by Kolařík et al. (2011). Only the asexual stage has been identified.

Recognition


The macroscopic symptoms can be observed. Yellowing and dieback commonly move into larger portions of the crown until the whole crown is impacted. With closer observation, beetle exit holes can be observed. Beetle galleries and darkened wood around the galleries are observed upon inspection of the phloem and cambium (Cranshaw and Tisserat, 2010;Tisserat et al., 2009).
For detecting the vector beetles, flight trapping has been conducted using funnel traps baited with the male-produced aggregation pheromone (Seybold et al., 2012). These traps can be deployed from March to November when the beetles are active, and checked every 7-10 days (USDA, 2014).

Symptons

Symptoms of Thousand Cankers Disease include yellowing and thinning of branches, resulting in branch dieback. As the disease progresses, overall thinning of crowns occurs, and death of trees can occur over the course of 2-3 years. With closer observation, exit holes of the walnut twig beetle Pityophthorus juglandis can be observed, and commonly cankers (darkened lesions) are present under the bark layer in the phloem where exit holes are observed (Tisserat et al., 2009). Cankers are usually small and circular at initial infection, but usually grow into oblong shapes around insect galleries. At advanced stages of the disease, basal sprouts will often be developed, but die within one to two years (Tisserat et al., 2009).
Mortality can occur either quickly or more slowly depending on the level of infestation and infection. It is assumed that Geosmithia morbida causes an annual canker and therefore that each site that is infested with Pityophthorus juglandis forms a canker, with death usually occurring from the coalescing of many cankers (Utley et al., 2013).

Impact

Thousand Cankers Disease is a disease complex native to the western United States that affects many Juglans and Pterocarya species, i.e. walnut and wingnut trees. It is caused by the fungus Geosmithia morbida, which is vectored by the walnut twig beetle (Pityophthorus juglandis), and possibly by other insects. The beetle carries fungal spores that are introduced into the tree during gallery construction, and the fungus then causes cankers in the inner bark that disrupt the flow of nutrients throughout the tree, often leading to its death. In recent years the disease has been reported in several eastern states, and also in Italy. Long-distance spread is thought to be a result of the movement of infected and infested wood.

Hosts

Geosmithia morbida affects trees in the genera Juglans (walnuts) and Pterocarya (wingnuts).

Biological Control
Castrillo et al. (2017) evaluated the use of the entomopathogenic fungi Metarhizium brunneum and Beauveria bassiana as biocontrol agents against the vector beetles. This study found that brood production was reduced when adult beetles were exposed to both pathogens.

Source: cabi.org
Description

The jungle myna is a 22 to 24cm grey-brownish bird with a tuft of feathers forming a small crest on the forehead and at the base of the bill which is not normally present on the common Indian myna (Acridotheres tristis). It has a black head with the upper areas being more grey-brown and the chin, breast and belly dark ashy-grey. It has a whitish underside, brownish wings and a typical yellow-orange beak. The jungle myna is sleeker than the common Indian myna and lacks the distinguishing yellow patch of skin on the posterior side of the eye. Interestingly, the colour of its iris is yellow in northern India, whereas in southern India, its bluish-white (Feare and Craig, 1999).

Impact

Acridotheres fuscus is native to India and south-east Asia and is now established in many Pacific islands. Acridotherea can be translated as "grasshopper hunter" - presumably an indication of its major food source in some parts of its native region. It is perceived as a problem to agricultural sectors dependant on crops. Both rural villages and urban areas are at risk of invasion. They feed off rubbish and food scraps and nest in any available spaces in houses and buildings. This behaviour and their close association with human habitations combine to cause a wide variety of problems for humans.


Source: cabi.org
Description

A. riparia can be an erect or sprawling herb to small shrub. Stems are cylindrical and have a purplish tint. Its green, opposite leaves can grow up to 15 centimeters long and 4 centimeters wide and range from lanceolate to narrow ovate. Leaves also display toothed margins. Flowers are arranged in flat-topped showy white clusters that produce 5-angled seeds 1-2 millimeters long and topped with 3-4 millimeter long bristles.

Impact

Ageratina riparia is unpalatable to livestock and is toxic. It reduces the carrying capacity of pastures and rangeland and restricts movement of machinery and stock. The weed has potential for rapid natural spread throughout its potential range (e.g., high reproductive potential and highly mobile propagules). A. riparia is a prolific seeder and grows very fast, becoming the dominant vegetation in an invaded area (Barreto and Evans, 1988). Leachates from leaves and plant litter have an allelopathic effect on other plants. A. riparia is among the primary threats to 25 endangered species on the island of Oahu in Hawaii. The potential negative impacts outweigh any limited value the species has as an ornamental.


Source: cabi.org
Description


Plants typically cespitose, occasionally stoloniferous or rhizomatous, especially when heavily grazed or under frequently mowed. Culms 20-80 cm long, stiffly erect;nodes glabrous or short hirsute. Leaves basal;ligules 0.5-1.5 mm;blades 5-25 cm long, 2.0-4.5 mm wide, flat to folded, glabrous or with long, scattered hairs at the base of the blade. Panicles 5-10 cm, fan-shaped, silvery reddish-purple;rachises 0.5-2 cm, typically with 2-8 branches;branches 3-9 cm, erect to somewhat spreading from the axillary pulvini, usually with only one rame;rame internodes with a central groove narrower than the margins, margins ciliate, with 1-3 mm hairs. Sessile spikelets 3.0-4.5 mm, narrowly ovate;lower glumes hirsute below with about 1 mm hairs, lacking a dorsal pit;awns 9-17 mm, twisted, geniculate;anthers 1-2 mm (Vega, 2000).

Impact

B. ischaemum is a warm seasoned perennial grass in the Poaceae family which is native to Europe, Asia and Africa. There are two varities of B. ischaemum, var. ischaemum and B. ischaemum var. songarica, which have different native ranges and have been introduced into different countries. This species was introduced into the North American Great Plains in the 1920s to tackle soil erosion and for forage production. This species has since been planted onto millions of hectares of marginal rangeland, roadsides and Conservation Reserve Program lands (Harmoney et al., 2004). B. ischaemum can readily escape original planting sites where it can invade native rangelands, with negative ecological and economic consequences such as the formation of monocultures and the loss of native biodiversity. This species is a particular problem in Texas where dense monocultures are displacing native grass species.


Source: cabi.org
Description

M. tuberosa is a woody vine, climbing, twining, 10-15 m in length, with abundant milky latex. Stems thick, cylindrical, glabrous. Leaves alternate;blades simple, 7-12 × 6-11 cm, 7-palmatilobed, the lobes elliptical, long-acuminate at the apex, the base cordiform, the margins revolute, slightly sinuate;upper surface dark green, slightly shiny, glabrous, with the venation sunken;lower surface pale green, dull, glabrous or puberulous, with the venation yellowish, prominent;petioles as long as the blade, cylindrical, glabrous or puberulous. Flowers functionally unisexual, solitary or in simple dichasia. Calyx yellowish green, the sepals unequal, 2-3 cm long, fleshy, accrescent and woody once the fruit is formed;corolla yellow, infundibuliform, 4-5 cm long, the limb 4-5 cm in diameter;stamens exserted, the anthers white;stigma bilobed, green, exserted. Capsules ovoid, opening irregularly, 1.5-2.5 cm long, light brown, with the sepals persistent and accrescent at the base;seeds 4 per fruit, black, obtusely trigonal, 1-1.5 cm long, velvety (Acevedo-Rodriguez, 2005).

Impact

M. tuberosa is a woody vine commonly cultivated as an ornamental which has escaped from cultivation and has become naturalized mostly in wet, mesic, and lowland forests in tropical and subtropical regions of the world (Austin, 1998;Wagner et al., 1999;Acevedo-Rodriguez, 2005). M. tuberosa is a fast-growing vine with the capability to reproduce sexually by seeds and vegetatively from discarded cuttings (PIER, 2014). Once established, it completely smothers tall forest canopies, killing host-trees and out-competing understory plants (Smith, 1985). It is included in the Global Compendium of Weeds (Randall, 2012) and is also listed as invasive in Florida, Cuba, St Lucia, Hawaii, and on several islands in the Pacific Ocean (Wagner et al., 1999;Florida Exotic Pest Plant Council, 2011;Graveson, 2012;Oviedo Prieto et al., 2012;PIER, 2014).


Source: cabi.org
Description

Thorny shrub or tree, usually 3 to 5 m (up to 12 m) in height. Stem diameters of 15 cm or more. Young and undisturbed plants have a single stem that may branch several times near the ground. As trees become older and heavier, they tend to lie down and produce new, vertical sprouts. Stems are covered by dark brown, shallowly furrowed bark. The inner bark is green. Twigs are greenish brown with 3 to 4 mm, curved spines. The alternate, compound leaves commonly have 4 to 22 pinnae each with 15 to 35 pairs of leaflets. Inflorescences are 6 cm spikes with paniculiform branching bearing many tiny, white flowers. The fruits, which are borne in clusters, are linear-oblong, flat, brown legumes, 4-5 cm by 5-6 mm in size. The seeds are yellow, flattened, and are approximately 4.5 mm by 5 mm in size (Francis, 2004).

Impact

Mimosa arenosa is native to Central and South America and has been introduced to regions of the Caribbean. It is an aggressive species that rapidly colonizes secondary forests, abandoned pastures, rangelands, roadsides, waste grounds and ruderal sites. This species often behaves as a weed in disturbed open sites where it grows forming thorny and almost impenetrable thickets that inhibit the germination and establishment of seedlings of other species, including native plants, altering natural successional patterns. Its high seed-set and dispersal capacity, and its ability to tolerate a remarkable range of habitats including disturbed sites, seasonally flooded areas, and low nutrient habitats are traits facilitating its rapid expansion. These traits suggest that M. arenosa has the potential to spread into many more new regions than it has to date.


Source: cabi.org
Description


Adapted from Flora of North America Editorial Committee (2014)

Impact


Russian thistles or tumbleweed of the genus Salsola are annual weeds, mostly native to Europe and Asia, but introduced globally. Salsola infests many tens of millions of hectares, especially in North America. S. paulsenii is a coarse, spiny annual weed native to Central Asia and introduced to North America. It tends to be found in drier and more lowland desert areas in the western USA as compared to other weedy Salsola species, with which it is often confused. S. paulsenii can be controlled by cultivation and chemicals, and a number of biological control agents have been tested. However, it is likely to remain a troublesome weed unless biocontrol eventually offers a viable option.

Biological Control
<br>The eriophyid mite, Aceria salsolae (Acari: Eriophyidae), was collected in Greece and evaluated for host plant specificity as a prospective biological control agent of invasive alien tumbleweeds in the USA, including S. paulsenii, S. tragus, S. collina and S. australis. The mite does not form galls, but is a vagrant that inhabits leaf and flower bud crevices, and feeding damage stunts the plant. The mite was able to multiply only on species in the Salsola section Kali subsection Kali, which includes the alien weeds Salsola collina, Salsola kali and Salsola paulsenii. It did not damage or multiply on Salsola soda, which is in a different section, nor on Halogeton glomeratus, which is in the same tribe. The mite reduced plant size by 66% at 25 weeks post-infestation under artificial conditions (Smith, 2005). Further studies concluded that there would be no significant risk to non-target plants as a result of using A. salsolae as a biological agent to control Salsola species in North America (Smith et al., 2009).<br>The search for biological control agents on related species continues, and a recent study found that a gall forming midge, Desertovelum stackelbergi Mamaev from Uzbekistan and a fungal pathogen, Colletotrichum gloeosporoides (Penz) from Hungary had much higher rates of attack and damage to S. tragus than S. australis (Smith et al., 2013). It is also clear that different agents have different impacts on closely related species, and so further work on taxonomic elucidation is required.

Source: cabi.org
Description

U. gibba is an annual or perennial submerged or free-floating aquatic plant. Rhizoids absent or present, filiform, branched. Stolons filiform, much branched, often mat-forming. Traps lateral on leaf segments, stalked, ovoid, 1-2.5 mm, mouth lateral;appendages 2, dorsal, branched, setiform, with shorter setae. Leaves numerous on stolons, 0.5-1.5 cm;primary segments (1 or) 2, unbranched or sparsely dichotomously branched into 3-8 ultimate segments;ultimate segments capillary, slightly flattened, margin entire or sparsely denticulate, apex and teeth setulose. Inflorescences erect, 2-15 cm, 1-3(-6)-flowered;peduncle terete, 0.3-0.5 mm thick, glabrous;scale 1, similar to bracts;bracts basifixed, semiorbicular, ca. 1 mm, minutely glandular, apex truncate and obscurely dentate. Pedicel erect to spreading, 2-12 mm, filiform;bracteoles absent. Calyx lobes subequal, broadly ovate to orbicular, 1.5-2 mm, apex rounded. Corolla yellow, 4-8 mm;lower lip slightly smaller than upper lip, base with a prominent 2-lobed swelling, apex rounded;spur narrowly conic to cylindric from a conic base, shorter or longer than corolla lower lip, distal part sparsely stipitate glandular, apex obtuse;palate densely pubescent;upper lip broadly ovate to suborbicular, ca. 2 × as long as upper calyx lobe, apex obscurely 3-lobed. Filaments 1-1.5 mm, curved;anther thecae confluent. Ovary globose;style evident;stigma lower lip transversely elliptic, upper lip obsolete. Capsule globose, 2-3 mm in diam., 2-valvate. Seeds lenticular, 0.8-1 mm in diam., margin broadly winged, wing shallowly and irregularly dentate;seed coat with small prominent reticulations (Zhenyu and Cheek, 2011).

Recognition


An interactive key for invasive plants in New Zealand has been developed by Dawson et al. (2010).

Impact

U. gibba is an annual or perennial submerged or free-floating carnivorous aquatic plant. It has been identified as such a specialist invasive species and may outcompete native bladderworts in lowland wetland ecosystems in countries where it is introduced. It was intentionally introduced, as an aquarium plant, to New Zealand in 1980, where it is now fully naturalized.

Biological Control
Sclerotinia sclerotiorum (Lib.) de Bary, a naturally occurring pathogen of many weeds, has been tested on U. gibba but did not show any potential as a control agent (Waipara et al., 2006).

Source: cabi.org
Description


Slightly modified from Flora of North America (2013)

Impact

P. persicaria is a species of knotweed native to the Americas. It has been introduced, presumably accidentally, to New Zealand, Pakistan and Hawaii, where it is found in shallow water, shores, marshes, swamps, the borders of ponds and small streams, drainage ditches and floodplain forests.

Biological Control
<br>The caterpillars of several moth species feed on Persicaria species in its native North America (see Notes on Natural Enemies;Illinois Wildflowers, 2013). However, P. punctata has not become a serious enough weed in its introduced range to warrant biological control yet.

Source: cabi.org
Description


Following Hong (1993) and Alaska Natural Heritage Program (2011)

Impact

Persicaria wallichii is a shrubby perennial herb up to 180 cm tall that originates from the temperate, western regions of Asia and the Indian subcontinent. It is naturalized in Europe, Canada and the United States, where it was introduced as a garden ornamental. It grows vigorously and creates large and dense stands that exclude native vegetation and prevent tree seedlings from growing. P. wallichii can greatly alter natural ecosystems and promotes the erosion of river banks. It is reported as invasive in its native range in northern India (Kala and Shrivastava, 2004), as well as in its non-native range in Belgium and the UK (Rich and Woodruff, 1996;Branquart et al., 2007). In the western USA it is a declared noxious weed in the states of Montana, California, Washington and Oregon (USDA-NRCS, 2015).

Biological Control
<br>Goats have been reported to eat P. wallichii, and in some circumstances controlled goat grazing may be an option similar to intensive mowing. The disadvantage of this approach is that the goats will graze on desirable vegetation as well as P. wallichii (Soll, 2004).

Source: cabi.org
Description

P. perfoliata is a prickly scrambling vine. It can reach a height of 6 m or more through climbing over shrubs and understory trees. The stems are elongated, branched and furrowed with short recurved prickles along the ridges. The thin, papery leaves are triangular, about 3-7 cm long and 2-5 cm wide, glabrous on the upper surface with prickles along the mid-rib on the underside (Zheng et al., 2005). The circular, saucer-shaped leafy structures, called ocrea, surround the stem at nodes. The inflorescences are capitate or spike-like racemes up to 2 cm long with clusters of 10 to 15 tiny flowers either terminal or in the axils of upper leaves (Kumar and DiTommaso, 2005). The flowers, 1-3 cm long, are borne on racemes. The fruits are attractive, deep blue and arranged in clusters at terminals, each containing a single glossy, black or reddish-black hard seed called an achene (NPS, 2009). Roots are fibrous and shallow.

Impact

P. perfoliata is a fast growing, spiny and herbaceous vine. Like many other members of the genus Persicaria, the plant is an aggressive and/or invasive weed. The plant scrambles over shrubs and other vegetation, and blocks the foliage of covered plants from available light, thus reducing their ability to photosynthesize. The leaves, petioles, and stems of P. perfoliata contain prickles, causing the movement of wildlife, and human activities to be impacted in infested areas (Okay, 1997). In its native China the plant has been used in Chinese medicine for over 300 years (Lou et al., 1988) and has rarely been recorded as an important noxious weed in either agriculture or the environment (Wang et al., 1990).

Hosts

P. perfoliata is not generally a weed of agricultural land (Wang et al., 1990), as it is removed during cultivation. However, the plant can be a pest in orchards, climbing on and covering horticultural crops. In the USA, the plant has a negative effect on Christmas tree farms, forestry operations on pine plantations and reforestation of natural areas (NPS, 2009).


Source: cabi.org
Description


The following has been adapted from Wilken and Hannah (1998), Hoban and Hoshovsky (2000), Flora of North America (2016) and the Encyclopedia of Life (2016).

Impact

E. glomerata is a perennial herbaceous plant in the Asteraceae that is native to Australia and New Zealand and has become naturalised in northwestern USA (in the states of Washington, Oregon and California). It is considered a problem invader in the Channel Islands, California, USA. It is able to quickly colonise and dominate disturbed areas such as those cleared by logging activity or fire. Along with other non-natives, it is potentially threatening native species in California.


Source: cabi.org
Description

Clayton et al. (2006) describes V. bromoides as the following

Impact


Weedy annual grasses like V. bromoides can reduce biodiversity on native grasslands, impede their restoration, and alter ecosystem processes. In pastures, V. bromoides reduces productivity, has low palatability, and its seeds can damage hides and wool of grazing animals. In annual crops like wheat, the species reduces yields (ISSG, 2012).

Hosts


In Canada, V. bromoides is one of several species named as threatening the habitat and therefore the survival of Rosy Owl-clover (Orthocarpus bracteosus) (Fairburns, 2002).


Source: cabi.org
Description

N. peltata is an aquatic, bottom-rooted perennial plant with round, floating leaves, yellow flowers borne upon peduncles rising above the water's surface, and long branching stolons with adventitious roots beneath the water’s surface. The circular to slightly heart shaped floating leaves are 3-15 cm in diameter on long stalks that attach to underwater rhizomes. The floating leaves have slightly wavy, scalloped margins and are alternately arranged at the stem base but are opposite at the apex (Flora of China, 2002). They are a green to yellow-green colour above, and are often a purple colour on the underside of the leaf. Each peduncle that rises a few inches above the water surface can have two to five flowers, which are bright yellow, have five distinctly fringed petals, and are 3-4 cm in diameter. Both long- and short-styled flower morphs are usually needed to sexually reproduce (Ornduff, 1966). The fruit is a 1.2-2.5 cm beaked capsule that contains many flat, smooth, ovoid seeds with winged margins. The seeds are approximately 0.4 mm thick, 3.8-5.1 mm long, and 2.7–3.0 mm broad (Cook, 1990). The seeds also have winged margins which aid attachment to avian vectors and floatation (Cook, 1990).

Impact

N. peltata is an aquatic, bottom-rooted perennial plant with floating leaves, which can grow in dense mats and reproduce prolifically through both vegetative and sexual means. These dense mats have caused many negative environmental and economic impacts, which include displacing native species, reducing biodiversity, decreasing water quality, impeding recreational activities, and diminishing aesthetic value. N. peltata is very difficult to control due to its ability to form a new plant from rhizomes, stolons, separated leaves, or seeds. The dispersal of N. peltata to new locations may be aided by the transport of seeds by avian vectors (Cook, 1990);however, the trade and potential escape of N. peltata through the water garden industry may play a larger role in its spread (Les and Mehrhoff, 1999). N. peltata is declared a noxious weed in New Zealand and parts of North America (NWCB, 2007), and is also declared as invasive in Sweden (Gren et al., 2007). Other species of Nymphoides also have the potential to become invasive, and N. indica and N. cristata have been recorded as problematic in Florida, USA.


Source: cabi.org
Description


Terrestrial ferns, plants stiff, erect. Rhizomes erect to decumbent, short-creeping, with dark brown scales. Fronds clustered at apex of rhizome, erect, (6-)15–60 cm tall, young fronds rosy pink;stipes dark brown, rough, up to 30 cm long, clothed with short dark fibrils and hairs;blades ± fan-shaped, deltate to ovate, dichotomously branched at 45º angle into 7–15 branches;pinnules asymmetrically oblong-rectangular to diamond shaped, 0.5–1.7 cm long, 3–8 mm wide, the upper and outer margins gently rounded, finely toothed, the lower straight and entire, softly pubescent to ± glabrate, veins mostly ending in marginal teeth;pinnule stalks 0.5–1 mm long. Sori 6–14 per segment, small, closely placed on upper and outer edges in notches between the lobes;indusium flaps 3–4(–5) mm wide, circular to broadly oblong or kidney-shaped, covered with numerous small, pointed brown hairs (Verdcourt, 2002;Palmer, 2003).

Recognition


This species can be detected by visual identification, facilitated by using a reference book (Heath and Chinnock, 1974) or key (Palmer, 2003).

Impact

A. hispidulum, the rosy maidenhair fern, is known to be invasive and weedy in the main Hawaiian Islands where it has escaped from cultivation. In Hawaii it is a serious weed generally of mesic slopes and gulch bottoms and is often abundant along intermittent and perennial streams. It is capable of invading intact plant communities and pristine areas. A. hispidulum usually begins to colonize in areas where there is some type of natural disturbance such as landslides, tree falls, disturbance by feral ungulates, or even a single dislodged rock. The dense clumps and rhizome mats of this fern prevent establishment of many native taxa including rare species. A. hispidulum can also overrun other ferns and herbs (Wilson, 1996;Palmer, 2003;H. Oppenheimer, Hawaii Plant Extinction Prevention Program (PEP), USA, personal communication, 2013). It is naturalized locally in a few other parts of the world including the southeastern USA and parts of its native range including eastern and southern Africa, Malaya, and Singapore.


Source: cabi.org
Description

T. arguens is an annual, caespitose grass. Culms erect;20–120 cm long. Leaves mostly basal. Ligule an eciliate membrane;1 mm long. Leaf-blade base broadly rounded. Leaf-blades flat, or conduplicate;5–30 cm long;4–7 mm wide. Leaf-blade apex acuminate. Inflorescence composed of racemes;terminal and axillary;subtended by a spatheole. Spatheole lanceolate;2.5–3.5 cm long;scarious;without tubercles;glabrous. Racemes 1;single;cuneate;bearing few fertile spikelets;bearing 1 fertile spikelets on each. Rhachis fragile at the nodes. Spikelets in threes (basal paired). Fertile spikelets sessile;1 in the cluster. Companion sterile spikelets pedicelled;2 in the cluster. Pedicels oblong;1 mm long;tip oblique. Basal sterile spikelets represented by a single scale;4 in number;forming an involucre about the fertile;with both pairs arising at about the same level;subsessile;6–10 mm long;equaling fertile. Basal sterile spikelet glumes smooth;glabrous;lower glume muticous. Companion sterile spikelets well-developed;comprising 2 subequal glumes without lemmas;lanceolate;6 mm long;shorter than fertile;separately deciduous. Companion sterile spikelet callus linear;2–3 mm long;truncate. Companion sterile spikelet glumes herbaceous;glabrous;acuminate. Spikelets comprising 1 basal sterile florets;1 fertile florets;without rhachilla extension. Spikelets elliptic;subterete;8–10 mm long;falling entire;deciduous with accessory branch structures. Spikelet callus linear;3 mm long;bearded;base pungent;attached obliquely. Spikelet callus hairs red. Glumes dissimilar;exceeding apex of florets;firmer than fertile lemma. Lower glume oblong;1 length of spikelet;coriaceous;dark brown;without keels;7 -veined. Lower glume surface pilose;hairy above. Lower glume hairs dark brown. Lower glume apex truncate. Upper glume oblong;coriaceous;with membranous margins;3 -veined. Upper glume surface pilose;hairy above. Upper glume margins ciliate. Upper glume hairs dark brown. Upper glume apex truncate. Basal sterile florets barren;without significant palea. Lemma of lower sterile floret oblong;2.8 mm long;hyaline;ciliate on margins. Fertile lemma oblong;3 mm long;hyaline;without keel;1 -veined. Lemma apex entire;awned;1 -awned. Principal lemma awn apical;geniculate;50–70 mm long overall;with twisted column. Column of lemma awn hispidulous. Palea absent or minute. Anthers 1.4 mm long (Clayton et al., 2014).

Impact

T. arguens is a fast growing and very aggressive grass. At present, this species has been listed as invasive in Jamaica and Fiji, and it is spreading across these islands displacing and outcompeting native grasses and herbs (IABIN, 2014;PIER, 2014). In areas invaded by this grass, livestock tend to avoid it for more palatable species resulting in the dominance of T. arguens over other low growing species (Motta, 1953). In addition, T. arguens seeds heavily and seeds can be easily dispersed by wind, vehicles, animals, and attached to clothes and mud. The practice of using dry grass stems as packing for provisions being carried to market is another common cause for the introduction and spread of this species (Motta, 1953;PIER, 2014).


Source: cabi.org
Description

The following description is from Lim (2014)

Impact

L. confusa is a perennial vine belonging to the honeysuckle family and is native to China, Nepal and Vietnam. It has long been used in traditional Chinese medicine. It is listed as an invasive species in Cuba and is also reported as one of the 46 most widespread invasive plants on the island of Réunion in the Indian Ocean. Despite this, there is no information available about its economic, social or environmental impacts or any methods for prevention or control of the species.


Source: cabi.org
Description

L. maackii grows to be a tall shrub, up to 6 m high. The leaves are opposite, lightly hairy, and have long, acuminate tips. The leaves range in length from 5-8 cm and are dark green above, paler beneath. Pairs of fragrant, tubular, white to pinkish flowers, fading to yellow bloom from the leaf axils in mid to late spring. Bright red fruits 5-6 mm in diameter mature from late summer into autumn (Zheng et al., 2006). The bark is a light grayish brown on mature stems.

Impact

L. maackii is a species of honeysuckle native to East Asia and primarily invasive in central and eastern USA and in Ontario, Canada. It grows as a tall, deciduous shrub in dense stands along woods edges, in disturbed forests and along riparian corridors, outcompeting native species for resources. Few insects feed on the plant, but birds and mammals spread the fruits. It may have allelopathic affects on neighboring plant species. L. maackii was heavily promoted and planted from the 1960s to the 1980s in the USA, but its popularity has since declined. It is still available for sale at some nurseries and online. It is listed as a Class B Noxious Weed in Vermont and sale and planting are prohibited in Connecticut and Massachusetts, USA. L. maackii is critically endangered in parts of its native range in Japan.

Hosts


Under experimental conditions, extract of L. maackii showed allelopathic affects against seeds in the Brassicaceae family, but no crop species were tested (Cippolini et al., 2012).

Biological Control
<br>No known biological controls exist (Batcher, 2000). A study of fungi and arthropods on in China identified several species that live or feed on L. maackii (Zheng et al., 2006). Few North American insects feed on L. maackii enough to impact its growth (Lieurance and Cippolini, 2012;2013).

Source: cabi.org
Description

L. morrowii is a deciduous, woody shrub with hollow stems and brown or grey bark that is ridged and peels off easily (Go Botany, 2018). It grows up to 2.4 m tall (Invasive.org, 2018). It has simple, untoothed, elliptical or oblong leaves that are 25-50 mm long, with two leaves per node (Go Botany, 2018). Leaves are hairy underneath and hairless or sparsely hairy on the upper surface (Go Botany, 2018). They are greyish and tomentose on the lower surface (IPANE, 2018) and have one main vein running from the base towards the tip, with secondary veins branching off at intervals (Go Botany, 2018). Peduncles are 5-15 mm and very hairy, and bractlets, sepals and corolla are also covered in downy hair (IPANE, 2018). Winter buds have three or more scales that overlap like shingles, with one edge covered and the other exposed (Go Botany, 2018).

Impact

Lonicera morrowii is a deciduous, woody shrub, native to Japan, China and the Republic of Korea. It was introduced to the USA from Japan in the 1860s as an ornamental, but has since escaped cultivation, is considered invasive and is prohibited in some states in the USA. It invades open woodlands, old fields and other disturbed sites, and spreads rapidly due to seed dispersal by birds and mammals. It can form a dense understory thicket which restricts native plant growth and tree seedling establishment. L. morrowii hybridizes with another non-native honeysuckle, L. tatarica, to produce L. x bella, and this plant is also considered invasive.


Source: cabi.org
Description


Planthoppers are insects that feed on plants by sucking sap from the plant tissues using their stylets (Backus, 1985). In general, leafhopper adults are often narrow and angular in appearance (Missouri Botanic Garden, 2016a).

Impact

Kallitaxila crini is a species of planthopper which has been introduced to Guam, the largest of the Mariana Islands in the Pacific Ocean, where it is a potential threat to an endangered tree species, Serianthes nelsonii. There is very little information about the distribution range and invasiveness of this species. It has been reported to be present on Honshu and the Bonin Islands of Japan and has been recorded as an invasive species in New Caledonia, however its specific impact does not appear to be documented.

Biological Control
<br>Introducing natural parasitoids and predators, and providing predators with alternative food sources for when planthopper populations are low, has been suggested as a way to control some planthoppers that are important agricultural pests (Weintraub and Wilson, 2010).

Source: cabi.org
Description


Adapted from Starr et al. (2003) and PIER (2013)

Impact

A. cordifolia is a succulent climbing plant native to South America that has proved to be very invasive in several countries where introduced, notably in Australia and on Pacific islands but also elsewhere. It smothers ground vegetation and, with its fleshy leaves and production of thick aerial tubers, it is so heavy that it easily breaks branches and can even bring down whole trees. It has shown itself to be a very damaging weed in moist forests, blanketing the ground and enveloping the canopy, restricting light and preventing the germination of native plants. A. cordifolia has been variously described as a ‘devastating weed’ that can ‘destroy a rainforest’. It has proved very difficult to control, but recent advances with biological control have shown potential following the release of the first agent in Australia in 2011.


Source: cabi.org
Description

S. cayennensis is a perennial evergreen herb or subshrub which can reach heights of 2.5 m. It has a woody glabrous stem with several branches. Leaves opposite, membranous, elliptic to broadly elliptic or ovate, 4-8 cm long, 2-4.5 cm wide, upper surface rugose, both surfaces glabrous or occasionally lower surface with a few scattered hairs usually along the veins and margins, margins sharply and coarsely serrate, the teeth conspicuously divergent, apex acute, base cuneate, petioles 0.5-2 cm long. Spikes slender, rachis flexuous to erect or somewhat nodding, 14-40 cm long, ca. 2.5 mm in diameter, the furrows somewhat shallow, nearly as wide as the rachis, bracts lanceolate, ca. 7 mm long;calyx ca. 7 mm long, the teeth subequal;corolla usually dark purplish blue with a paler center, the tube 7-8 mm long (Wagner et al., 1999).

Impact

S. cayennensis is a shrub native to South and Central America and the Caribbean. It was introduced widely introduced into several tropical countries around the world as an ornamental species due to its attractive blue flowers, but in some countries it has become invasive. S. cayennensis has a wide environmental tolerance and often invades disturbed areas where it can outcompete native flora. It is invasive in many Pacific islands and is regarded as a noxious weed in the Northern Territory, Australia and is increasing in abundance in Florida, USA. According to a risk assessment this species is regarded as being highly invasive (score 20 = high risk) (PIER, 2015).

Hosts

S. cayennensis may outcompete smaller native plant species and crops dedicated to livestock are often affected by smothering. In Australia, this species is commonly found as a weed of pastures and sugarcane (Saccharum species) (DAFF, 2014).

Biological Control
<br>No biological control agents have been released for S. cayennensis, however possible agents are discussed by Waterhouse and Norris (1987). The potential for biological control of the closely related species S. jamaicensis is discussed in detail by Cock et al. (1985).

Source: cabi.org
Description

C. debeauxii is an erect perennial herbaceous plant growing to 80 cm tall. Young plants have a strong tap root which may develop into a tough crown of several roots as plants mature. The basal rosette leaves are entire to deeply lobed and slightly hairy;stem leaves are small and without a stalk (sessile). Growth is openly branching, stems are slender and somewhat rough to the touch.

Impact

Centaurea debeauxii, a fertile hybrid of C. nigra and C. jacea, is an invasive perennial of pasture and natural grasslands with an increasing non-native distribution in wet temperate areas of continental North America, now also recorded in South America and Australia. Favouring mesic and moist situations, it can form dense stands, outcompeting native grasses and displacing broadleaved species. It is listed as a noxious weed in several western US states as well as one Canadian province. In natural and semi-natural plant communities, it threatens rarer endemics such as the rough popcorn flower (Plagiobothrys hirtus).


Source: cabi.org
Description

Perennial. 50-170 cm tall. Several to many erect stems from a woody, tap-rooted crown are unbranched or sparingly branched distally, villous with septate hairs, thinly arachnoid-tomentose, swollen below the capitula. Leaves are also short-villous and thinly arachnoid, ranging to almost glabrate, dotted with resinous glands. The basal and lower cauline leaves are borne on petioles;blades are oblanceolate to narrowly ovate, 10 to 30 cm, with entire or shallowly dentate margins. Cauline leaves are sessile, shortly decurrent, gradually becoming smaller up the stem, especially the cluster of leaves just below the heads;blades lanceolate to ovate, 5 to 10 cm long, margin entire or slightly undulate, apices acute. Heads subtended by a cluster of reduced leaves. Involucres ovoid to hemispheric, 25-35 mm, surrounded by 3 to 12 rows of layered phyllaries. Phyllary base (body) pale-green to straw-coloured, ovate to broadly lanceolate, glabrous;phyllary appendages erect to spreading, brown to golden, scarious, abruptly expanded forming a cup, 1-2 cm wide, normally concealing the basal parts, lacerate fringed, sometimes tipped by weak spines 1-2 mm, glabrous. Florets many;corollas yellow;corollas of sterile florets slightly expanded, ca. 4 mm;corollas of disc florets ca. 3.5 mm. Cypselae 7-8 mm;pappi of flattened bristles, 5-8 mm long (Roché, 1991;Keil and Ochsmann, 2006).

Impact

C. macrocephala is a robust perennial that has been in cultivation for over 200 years. It was reportedly introduced to the UK in 1805 and its presence in the USA dates back to at least 812, when Thomas Jefferson grew it at Monticello from seeds from Philadelphia nurseryman, Bernard McMahon (Anon., 2009). It is still widely used in the horticultural trade. It is listed as a Class A noxious weed in Washington State, USA (USDA-NRCS, 2011) and is a prohibited noxious weed in Alberta, Canada (CIPM, 2011). It threatens natural meadows and spreads in disturbed areas and once established is difficult to control.

Hosts

C. macrocephala has primarily invaded communities already dominated by perennial plants: meadows;pastures;bluegrass sod;and perennial grass openings in forested areas (Roché, 1991).


Source: cabi.org
Description


Annual herbs, 10-40 dm tall;stems simple below, branching above, tomentose when young. Leaves usually lanceolate in outline, with deeply sinuate or lobed, spiny margins;lower surface whitish tomentose. Lower leaves up to 45 cm long and 18 cm wide, with long decurrent base, upper leaves to 10 cm long and 6 cm wide, truncate or lyrate. Inflorescence of terminal clusters of 3-5 or single heads on short peduncles arising from the axils of the upper and middle leaves. Heads with the involucre 8- or 9-seriate, 3-3.5 cm tall, 1.5-2 cm in diameter at the base, the outer involucral bracts 4-6 mm long, basally 1-2 mm wide, with a glutinous dorsal ridge, tapering to a 5-7 mm long spine, the innermost bracts 25-35 mm long, 1-2 mm wide, tapering, twisted and often purple near the tip;corolla purple to reddish, 26-30 mm long, the lobes 4-5 mm long, anthers colourless, 4-5 mm long, style purple 27-31 mm long. Achenes 4-5 mm long, 1-1.5 mm in diameter;pappus 23-25 mm long (Flora of Panama WFO, 2013).

Impact

C. mexicanum is a cosmopolitan herb included in the Global Compendium of Weeds (Randall, 2012). This species has been classified as invasive in Cuba (González-Torres et al., 2012) and Puerto Rico, and as an agricultural and environmental weed within its native distribution range which includes Mexico and Central America (Randall, 2012). This species is a fast-growing herb which spreads by seeds and produces a large number of bristled seeds which can be easily dispersed by wind (Pruski, 2013).

Hosts

C. mexicanum is listed as a weed which principally affects active pastures. In these areas, rosettes can grow forming dense monospecific stands. Previous studies have suggested that cattle do not feed on these plants (Cardenas and Coulston, 1967).


Source: cabi.org
Description


The following description has been adapted from the Flora of North America Editorial Committee (2016).

Hosts

Aminidehagui et al. (2006) noted that L. perfoliatum has allelopathic effects on the roots of lettuce (Lactuca sativa).


Source: cabi.org
Description


Annual or biennial herbs 0.3–1.5(–2.2) m tall, with a long slender taproot. Stems solitary, erect;branches ascending, glabrous. Basal rosette leaves triangular-ovate to oblanceolate, 80-370 mm long, 2.5-180 mm wide, lyrate pinnatifid, hairs only on veins, on petioles 20-40 mm long;bases attenuate to clasping;margins dentate;lateral lobes 1 to 3 pairs, triangular;terminal lobes not distinctly larger than lateral ones;apices rounded to acute. Cauline leaves alternate, large diminishing and less divided toward stem apex;bases clasping;apices acute. Synflorescences paniculate, 0.4-0.8 m long. Capitula terminal on 10-20 mm peduncles, each with 10–27 florets. Involucres cylindric, 8–14 mm long, 4-5 mm diam.;outer phyllaries 5-8 lanceolate 2-7 mm long, erect;inner phyllaries 6-9 linear 6-10 mm long. Florets all ligulate, 5-7 mm long, linear, bluish-white. Cypselae brown, subcylindric to compressed 4-6 mm long, speckled rugulose with 4-6 ribs;beaks 0.1-1 mm long. Pappus numerous barbellate bristles 4-5 mm long, white (description compiled from Strother 2006;Weakley et al. 2012;Puttock pers. obs.).

Impact

L. floridana is a weedy lettuce which can grow to almost 2 metres tall (Randall, 2012), locally common in disturbed areas within its native range and only found outside North America in Puerto Rico, where it is considered invasive. It is a fast-growing, annual or biennial herb of gardens, roadsides, waste ground and pastures, and is native to moist and wet woodlands in North America.


Source: cabi.org
Description


Herbaceous, perennial vine;branching stem obscurely 6-angled to terate, ranging from glabrous to densely pilose;8-15 cm internodes. Petioles glabrous or puberulent, 20-50 mm. Triangular to triangular-ovate leaf blades, 3-15 x 2-11 cm with cordate to hastate bases;margins subentire to undulate, crenate, or dentate, apices acuminate (tips often caudate), faces puberulent. Produces dense corymbiform flowers, with small heads 5-7 mm long. Corollas generally pinkish to purplish, occasionally white, 3-5.4 mm, dotted sparsely with glands, lobes triangular to deltate. Cypselae dark brown to blackish, 1.8-2.2 mm, also dotted with glands;pappi of 30-37 white or pinkish to purplish bristles 4-4.5 mm. Fruits are oblong 1-.5-2.5 mm long, brownish black, five angled resinous achenes;Chromosome number 2n=38 (Holm et al., 1991;Flora of North America Editorial Committee, 2013).

Biological Control
<br>There have been some reports of efforts to control M. scandens by classical biological control using the thrips, Liothrips mikaniae from Trinidad (Waterhouse and Norris, 1987). However, due to the location of these releases (outside of North America)and the distribution of M. scandens, it is likely that M. micrantha was the actual target.<br>It may be possible to manage Mikania species in some areas through livestock grazing.

Source: cabi.org
Description


The following description is adapted from Flora of North America Editorial Committee (2015).

Impact

A. semibaccata is a low-growing shrub native to Australia. It is valued as a fodder plant and, along with many other Atriplex species, has been introduced around the world as a drought and salt tolerant forage. It was introduced to the USA where it has escaped cultivation and is now invasive in coastal grasslands, scrub and saline area, where it can form a dense cover inhibiting the growth of native plants. The California Invasive Plant Council classifies its potential impact on native ecosystems as moderate and control and eradication of this species appears possible. Many other Atriplex species are beginning to be reported as somewhat invasive in other parts of the world and the genus merits further attention in this regard.


Source: cabi.org
Description


A stout, erect, perennial, rhizomatous grass, up to 120 cm high. Rhizomes spreading horizontally and vertically;the younger parts of the rhizome with white coherent pith and bearing yellowish-white overlapping scale leaves;the older parts yellow-brown and hollow, the scale leaves mostly perished. Roots white and fleshy when young, becoming brownish and wiry with age, up to four per node. Aerial shoots formed mainly along the vertical rhizomes, forming dense tufts;the stems of the aerial shoots form elongated internodes when buried, thus becoming vertical rhizomes. Leaves up to 6 mm wide and 60 cm long, but sometimes as much as 90 cm long, sharply pointed, usually tightly inrolled, except under moist conditions;the abaxial surface greyish-green and smooth, without distinct ribs, the adaxial surface glaucous, closely ribbed with ribs densely and minutely hairy;sheaths overlapping. Ligule up to 2.5 cm long, acuminate, split at the top when young and usually torn when older. Panicle 7-15 cm long, dense, stout, spike-like, narrowly oblong to lanceolate-oblong, tapering upwards, whitish, branches erect. Spikelets 10-16 mm long, compressed, narrowly oblong, gaping when dry, with one floret. Glumes slightly unequal, whitish, keeled, slightly pointed, margins hyaline, keel serrate, exceeding the lemma and palea;lower glume 1-nerved, upper glume 3-nerved. Lemma lanceolate, minutely rough, 5-7-nerved, keeled, 8-12 mm long, with two short points at the top, and a short stout awn less than 1 mm long in between;surrounded at the base with fine hairs c. 1/3 of the length of the lemma. Palea 2-4-nerved, compressed, acute, keeled, shortly ciliate on the keel. Lodicules c. 1 mm long, tapering. Stamens three, 4-7 mm long, up to ten times as long as wide, hanging outside the floret. Styles short. Ovary glabrous. Grains brown, obovate, shed while still enclosed by the hardened lemma and palea (Huiskes, 1979).

Impact

A. arenaria is a grass species specially adapted to growing on sand dunes. It is native to Europe and western Asia and has been introduced as a very effective sand binder to a number of other countries but has become a problem in many of these. In the countries to which A. arenaria has been introduced it invades coastal sand dunes, thriving in areas of active sand movement. In such places it not only disturbs and replaces native vegetation but can also change the topography and composition of whole foredune systems. In the USA, it has replaced the foredune vegetation, greatly reducing biodiversity, and the foredune topography has changed to much steeper slopes and whilst dune ridges further inland used to be perpendicular to the coast they are now parallel to the coast (Russo et al., 1988). In California it is negatively impacting on a number of endangered species of plants. It is reported as a major alien invader in Australia, New Zealand and South Africa where it is also having a negative environmental impact.

Hosts


In North America, A. arenaria has escaped from plantations and has become naturalized north of San Francisco where it now dominates beaches formerly dominated by Elymus mollis [ Leymus mollis ] (Russo et al., 1988). Despite L. mollis being more salt tolerant than A. arenaria, A. arenaria can withstand sand accumulation of up to 1 m per year (Willis et al., 1979).
In Australia, native beach plants most commonly affected are beach spinifex (Spinifex sericeus), beach fescue (Austrofestuca littoralis), dune sedge (Carex pumila) and glistening saltbush (Atriplex billardieri). In addition to A. littoralis and S. sericeus, in New Zealand the native species affected by the spread of A. arenaria include pingao (Desmoschoenus spiralis [ Ficinia spiralis ]) and New Zealand sea spurge (Euphorbia glauca).

Biological Control
<br>Few insect or fungal species have been found to feed or live exclusively on this species and biological control has not been considered.

Source: cabi.org
Description

A. argentea is an annual herb producing branching stems which can reach a height of 15-80 cm (Kadereit et al., 2010). Stems are decumbent to erect, densely branched, finely gray-scaly, peeling. The leaves are elliptic to deltate, grey-scaly, wavy-margined and usually triangular to roughly oval and 1-4 cm long. Staminate flowers emerge from June to September in small sessile axillary glomerules and terminal, interrupted spikes in distalmost bracteate leaves (Welsh et al., 1993). The inflorescences are rough clusters of tiny flowers, with male and female flowers in separate clusters. The inflorescence is pistillate with bracts in fruit 4–8 mm, fused to near top, widely deltate to round, generally tubercled, margins green, toothed. Seed 1.5–2 mm, brown with radicle either superior or lateral (Kadereit et al., 2010).

Impact

A. argentea is an annual herb, commonly known as silverscale saltbush. It is native to North America from southern Canada to northern Mexico, where it grows in many types of habitat (e.g. railroads and open, disturbed areas), generally on saline soils. It has been introduced to Argentina (Ferrando et al., 2003) and Denmark (in 1917;NOBANIS, 2015) but its distribution is scarce and it has not been characterized as invasive in these areas (NOBANIS, 2015). In California, USA, it has been reported, alongside other weedy species, as rendering habitat unsuitable for the endangered San Joaquin kit fox (Vulpes macrotis mutica) (US Fish and Wildlife Service, 2010). Many other Atriplex species are reported as invasive in different parts of the world and species of the genus merits further attention in this regard.


Source: cabi.org
Description

The following description is adapted from Miller (1988) and Flora of Panama (2018)

Impact

Heliotropium curassavicum is an aggressive weed that rapidly colonizes new areas, in particular on disturbed saline soils and coastal areas in arid and semiarid habitats. It forms dense monospecific stands that displace native vegetation and alter successional pathways. A combination of traits, such as high seed germination and seedling establishment rates in open areas, along with its ability to shift between sexual reproduction to clonal growth (i.e., adventitious root buds) are responsible for the invasiveness and rapid spread of H. curassavicum. H. curassavicum has become one of the most common weeds in the Mediterranean Basin and the Nile Delta, where it is regarded as a serious ecological and agricultural problem, but it is also listed as invasive in countries across Europe, the Arabian Peninsula, Africa and in Anguilla in the Lesser Antilles.


Source: cabi.org
Description

Erect, herbaceous annual, 0.5–1(–1.5) m tall, branched and with a long tap root with few secondary roots. Stems and petioles thickly covered with glandular hairs, rarely glabrous, varying in colour from green to pink, or violet to purple. Leaves alternate, digitately palmate, (3–)5(–7) leaflets, sessile, pinnately dissected, sparsely hairy, obovate to elliptic, 2–10 cm long, 2–4 cm wide, finely toothed margin or rounded ends, petioles 3–23 cm long. Inflorescences showy, up to 30 cm long, terminal and axillary determinate racemes;flowers arise singly in axils of small sessile and trifoliate to simple bracts which are smaller than the leaflets;flowers 1–2.5 cm in diameter;pedicels long;4 sepals, free, ovate to lanceolate, up to 8 mm long, glandular;4 narrow clawed petals, 6 stamens with long purple filaments arising from an elongated gynophore;style short extending to a purple capitate stigma depressed at the apex;ovary bicarpellary syncarpous, unilocular with numerous ovules on parietal placentation, a false septum develops during fruiting;petals white, pale pink or lilac;floral formula K 4 C 4 A 6 G(2). Fruit long stalked silique, spindle shaped, 12 cm long, 8–10 mm wide;green in colour and yellow when ripe;easily dehiscent when dry releasing seeds. Seeds numerous, 1.0–1.5 mm in diameter, suborbicular, sharply tuberculate with many concentric ribs and irregular cross ribs;grey-black in colour;seed cleft narrow. Seedlings have oblong cotyledonary leaves, hairy petioles and petiolate trifoliate to elliptical leaflets. Terminal leaflet generally larger than lateral leaflets (Chweya and Mnzava, 1997;Raju and Rani, 2016).


Source: cabi.org
Description


Perennial, climbing, woody vine with numerous lateral branches that climbs by means of tendrils and attains 5-8 m in length. Stems almost cylindrical, striate, glabrous;cross section with a single vascular cylinder. Leaves alternate, biternate;leaflets chartaceous, glabrous except for some hairs on the veins, the margins deeply serrate;terminal leaflet rhombic, 4.5-8 × 2-4 cm, the apex acute or acuminate, the base cuneate or attenuate;lateral leaflets oblong-lanceolate, 2.7-7 × 1.3-3cm, the apex acute or acuminate, the base obtuse or attenuate;rachis and petiole not winged, canaliculate;petioles 1-5 cm long;stipules minute, early deciduous;tendrils in pairs, spirally twisted, at the end of short axillary axes (aborted inflorescences), from which an inflorescence usually develops. Flowers functionally unisexual, zygomorphic, in axillary racemiform thyrses;cincinni more than 4, usually in more than one whorl. Calyx light green, of 4 sepals, the two outer ones ca. 1.7-3 mm long, the inner ones ca. 5-8mm long;petals white, obovate, 6-9 mm long;petaliferous appendages slightly shorter than the petals, fleshy and yellow at the apex, forming a hood that encloses the apex of the glands of the disc;disc unilateral, with 2 elongate glands, corniform, whitish, 1.2-2 mm long;stamens 8, the filaments unequal, glabrous or pubescent;ovary ovoid or ellipsoid, villous, with one style and 3 stigmas. Capsule membranaceous, inflated, ellipsoid or ovoid, 3-5.5 cm long, stramineous when ripe. Seed one per locule, spherical, black,4-5.5 mm in diameter, with a white, obtuse triangular hilum (Acevedo-Rodriguez, 2005).


Source: cabi.org
Description

I. ochracea is a slightly woody vine, twining, attaining 5 m in length, with scarce watery latex. Stems are cylindrical, slender, and pubescent. Leaves are alternate;blades simple, 3-10 × 2.5-7.5 cm, ovate, chartaceous, glabrous except for some hairs on the veins, the apex acuminate and usually mucronate, the margins entire or sinuate;upper and lower surface with the veins slightly prominent, the lower surface usually glaucous;petioles 2-6 cm long, pubescent. Flowers solitary or in double dichasia, axillary;peduncles slightly longer than the petioles;bracts ovate, approximately 1.6 mm long. Calyx green, not accrescent, of 5 subequal sepals, 5-7 mm long, chartaceous, ovate or oblong-ovate, glabrous, punctate;corolla pale yellow, with the base of the tube purple inside, infundibuliform, 3-4 cm long, the limb with 5 shallow, rounded lobes;stamens and stigmas white, not exserted. Capsule ovoid, glabrous, with a thin pericarp, 1.3-1.6 cm long, stramineous, with the sepals persistent, not accrescent at the base;4 seeds per fruit, 4-5 mm long, black, dull, glabrous (Acevedo-Rodríguez, 2005).

Impact

I. ochracea is a vine species included in the Global Compendium of Weeds (Randall, 2012). It is listed as invasive in Hawaii, New Caledonia, Puerto Rico and the Virgin Islands where it is also considered a weed mainly in ruderal and disturbed sites (Wagner et al., 1999;Acevedo and Strong, 2012;Randall, 2012). I. ochracea was introduced as an ornamental species from Africa into new habitats throughout the tropics. It has escaped from cultivation and has successfully colonized natural areas in coastal and riparian forests, thickets, grassland, river edges, river banks and disturbed sites (Goncalves, 1987;MacKee, 1994;Wagner et al., 1999).


Source: cabi.org
Host plants Datura ferox, Datura Long, Short
Title: Datura ferox
Description

D. ferox is an annual herb growing 50-150 cm tall. Stems are hairless or sparsely hairy with short and soft hairs, frequently branched and often purplish towards the base. Leaf shapes range from broadly ovate to rounded-triangular, 8-14 cm long and 6-16 cm wide;leaf margins are irregularly serrated or sinuate (with deep wavy margins). Flowers are white, often tinged with violet, 4-6 cm long, with five lobes, each lobe ending in a point of 1-2 mm length. Anthers are 3-4 mm long. Fruits are ellipsoid capsules up to 4 cm long. Each capsule bears up to 60 stout spines, the upper ones being longer than the lower ones. Seeds are black or grey and 4-5 mm long (George, 1982).

Recognition

D. quercifolia can be distinguished from D. ferox by more purplish coloration in foliage;corolla and anthers, slightly downy versus glabrous;and spines somewhat less stout (Houmani et al., 1999).

Hosts

D. ferox is a weed in summer crops, including maize, soybean, peanuts, grain sorghum, potato, sunflower and Cucurbitaceae (Parsons and Cuthbertson, 2001;Torres et al., 2013a,b).


Source: cabi.org
Title: Datura ferox
Description

D. annulatum is a perennial grass with culms 25-100 cm tall, ascending, nodes pubescent. Sheaths lax, terete, 3-4 cm long, glabrous except finely pubescent on margins near throat;ligule a shallow membrane, approximately 1.5 mm long;blades linear-acuminate, 3-30 cm long, 2-7 mm wide, margins sparsely pubescent, apex attenuate, base subcordate. Inflorescences composed of (1) 2-15 subdigitate, short-pedunculate racemes, each raceme 3-7 cm long, peduncles glabrous;spikelet pairs subimbricate along a slender filiform axis, with 0-6 smaller homogamous spikelet pairs at base, the joints and pedicels flattened, margins setose;sessile spikelet narrowly oblong, 2-6 mm long, first glume cartilaginous, slightly concave, villous below the middle, pubescent with long bulbous-based hairs above the middle, obscurely nerved, margins inflexed, apex obtuse to subacute, second glume narrowly boat-shaped, 2-6 mm long, 3-nerved, scabrid on back of the midnerve toward apex, obscurely scaberulous over the back toward apex, hyaline, first lemma delicately hyaline, oblong-rounded, setose near tip, approximately 2 mm long, palea absent, second lemma linear, approximately 1.6 mm long, hyaline, with the central nerve excurrent as a geniculate, twisted awn 8-25 mm long;pedicellate spikelet with first glume narrowly ovate-truncate, approximately 3 mm long, 11-nerved, pectinate-setose along the back of the inflexed margins, midnerve setose on the back toward apex. Caryopsis oblong to obovate, dorsally compressed, approximately 2 mm long (Wagner et al., 1999).

Impact

D. annulatum is a perennial grass widely naturalized in tropical and subtropical regions of the world where it has been intentionally introduced. This grass species is used for grazing and for hay and silage (Barkworth et al., 2003;Cook et al., 2005;FAO, 2014). It has escaped from cultivation and has become a weed in the United States, Australia, Mexico, Central America and the West Indies (Villaseñor and Espinosa-García, 2004;Chacon and Saborío, 2012;Gonzalez-Torres et al., 2012;Randall, 2012;USDA-NRCS, 2014). D. annulatum has been intentionally introduced as a pasture grass because of its capability to establish on a wide variety of soils (including poorly drained soils), and its salinity and drought tolerance (i.e., 6- 8 months dry seasons;Cook et al., 2005). It competes aggressively with other plants and grows forming dense stands (Vibrans, 2011). D. annulatum also tolerates seasonal burning (Cook et al., 2005).

Hosts


In Australia, D. annulatum is competing aggressively with important native grasses such as the species Eriachne benthamii. In Texas (USA), this species has escaped from pastures and is outcompeting native grasses in bluestem coastal grassland communities (Queensland Department of Primary Industries and Fisheries, 2011).


Source: cabi.org
Description

Perennial aquatic or semi-aquatic herb. Stem highly variable, rooting in mud and freely branching or elongating in deeper water. Leaves alternate and whorled on same plant, pinnately divided, with submersed leaves having three to five pairs of divisions. Emersed leaves are 0.5-3 cm long, linear to lance-shaped, and have comb-like divisions or sharp teeth. Flowers either male or female, found on the same plant (monoecious), some bisexual, borne in a terminal spike above the water surface, with male flowers near the inflorescence tip. Bracts are longer than male flowers, triangular, with six to ten 1-2 mm long teeth that are angled toward the tip. Flowers green to purplish, small, four-parted, with 1.5-2 mm long petals that are rounded above and narrow-clawed. Fruit is a deeply four-lobed nut-like cluster, pale, 1.3-2 mm long, egg-shaped to cubic, splitting into four one-seeded segments that are flat-sided with two spiked ridges. Winter buds absent (Red de Herbarios del Noroeste de México, 2017).

Impact

Myriophyllum pinnatum is a perennial aquatic herb only reported as invasive in Cuba, where it is included in the management plan of the Ciénaga de Zapata Biosphere Reserve as a species that needs to be managed to prevent invasion of that wetland system. In some areas of its native range in North America, it is considered rare, endangered or extirpated due to habitat fragmentation and loss. In the USA, the species is considered endangered in Connecticut, Massachusetts, Indiana, New Jersey, New York, Rhode Island and Tennessee. M. pinnatum belongs to a genus recognized for the invasive species M. spicatum, M. aquaticum and M. heterophyllum.


Source: cabi.org
Description

H. coccineum is a vigorous perennial herb. Pseudostems grow up to 1.5-2 m height. Leaves sessile;ligule 1.2-2.5 cm;leaf blade narrowly linear, 25-50 × 3-5 cm, glabrous, base subrounded or attenuate, apex caudate-acuminate. Spikes cylindric, usually dense, glabrous or sparsely villous;bracts oblong, 3-3.5 cm, leathery, sparsely pubescent, rarely glabrous, 3-flowered, margin involute or rather flat, apex obtuse or acute. Flowers red. Calyx ca. 2.5 cm, sparsely pubescent especially at 3-toothed apex. Corolla tube slightly longer than calyx;lobes reflexed, linear, ca. 3 cm. Lateral staminodes lanceolate, ca. 2.3 cm. Labellum orbicular, ca. 2 cm wide or rather small, apex deeply 2-cleft. Filament ca. 5 cm;anther 7-8 mm. Ovary sericeous, 2.5-3 mm. Capsule globose, approximately 2 cm in diameter. Seeds red. (Flora of China Editorial Committee 2012).

Impact

Hedychium coccineum is an adaptable, tall, herbaceous, and very variable ornamental plant native to Asia. It can colonise natural or semi-natural habitats, from riverine fringe and mountain grasslands to forest understorey. In its introduced range, it can become dominant or co-dominant in natural or semi-natural environments, competing with and displacing indigenous species (e.g. in La Réunion, Africa;Brazil;South Africa). Similarly to other Hedychium species (i.e., Hedychium gardnerianum and H. coronarium), it is widely traded as a garden ornamental around the world. H. coccineum is included in the Global Invasive Species Database (2014) and the Global Compendium of Weeds (Randall, 2012) and is a declared weed and invasive species in some countries. Its environmental adaptability, high commercial appeal and growing impact in countries where it has established suggest its prospective spread in delicate ecosystems cannot be underestimated.

Hosts


Infestations of H. coccineum have been reported in plantations in South Africa as well as limited access to plantations caused by the plant (Henderson, 2001).

Biological Control
<br>None specifically for H. coccineum but a biocontrol initiative by CABI for a consortium of funders from New Zealand and Hawaii, USA, for Hedychium gardnerianum is ongoing and records/specimens of insects and diseases associated with all Hedychium congeners are being collected as part of the project (Djeddour D, CABI, personal observation, 2014).

Source: cabi.org
Description


The following description is from Brooks and Clemants (2000): A rhizomatous, perennial herb (graminoid), typically growing in dense clumps 20 – 60 cm tall. Rhizomes 2--3 mm diam. Culms erect, 2--6 mm diam. Cataphylls 0 or 1--2, straw-colored, apex narrowly acute. Leaves: basal 1--3, cauline 2--6, straw-colored;auricles absent;blade 2--25 cm x 1.5--6 mm. Inflorescences panicles or racemes of 2--50 heads or heads solitary, 2--14 cm, erect or ascending branches;primary bract erect;heads 3--70-flowered, obovoid to globose, 7--11 mm diam. Flowers: tepals green to brown or reddish brown, lanceolate;outer tepals 2.7--3.6(--4) mm, apex acuminate;inner tepals 2.2--3(--3.5) mm, nearly equal, apex acuminate;stamens 3 or 6;anthers ½ to equal filament length. Capsules included to slightly exserted, chestnut to dark brown, 1-locular, oblong, 2.4--4.3 mm, apex obtuse proximal to beak. Seeds elliptic to obovate, 0.4--1 mm, occasionally tailed.

Recognition

J. ensifolius is a low-statured plant that would be difficult to detect remotely, although ditchlines and areas with wet soil and shallow standing water that can be identified from images should be targeted in surveys. It can be readily identified visually by its combination of flattened leaves and dark, globular seedheads. Similar species can be readily distinguished as described in the ‘Similarities to Other Species’ section.

Impact

Juncus ensifolius is a mostly pioneering or ruderal species of rush that readily establishes in disturbed wet soils, often from buried seeds. Within its native range in western North America it is widespread and infrequent to common, typically a minor, secondary or at most co-dominant species in natural wetlands. Limited reports suggest that it behaves similarly in east Asia (Tachibana et al., 2001), where it is also native. Although it is recognized as having “potential for weediness” (Marr and Trull, 2002), it is not generally viewed as an aggressive invader within its native range and is widely used in wetland restoration and as a landscape plant. There are no published studies documenting its rate of growth, spread or dispersal.

Hosts


There is no evidence that J. ensifolius currently causes significant economic damage to any crop plants, although it apparently occurs as a minor contaminant in grass seed mixes (Piirainen, 2004) or commercial peat (Kirschner, 2002). It is recorded as a competitor of seven endangered species in Hawaii – see the 'Host Plants/Plants Affected' and 'Threatened Species’ tables for more information.

Biological Control
<br>Although J. ensifolius has a number of natural enemies (see ‘Natural Enemies’ section), there are no reports of their use for biological control.

Source: cabi.org
Title: Juncus tenuis
Description


The following is modified from PIER, 2016, after Wagner et al., 1999

Impact

Juncus tenuis, commonly known as slender rush, is a clump-forming, tufted perennial herb. In its native environment in the Americas, J. tenuis is not usually considered ‘weedy’ since it is relatively small and commonly grows as a plant of pathways and road verges. It is named as a minor weed of alfalfa in Oklahoma, USA. It has also been reported to sometimes invade urban lawns and to cause problems on golf courses in North America. It has been introduced to parts of Asia, Africa, Europe and Oceania, most probably unintentionally since seeds are sticky and readily attach to animals, clothes and car tyres. It is regarded as invasive in Hawaii (PIER, 2016). It has also been recently reported among invasive species in Croatian forestry (Horvat & Franjic, 2016).

Biological Control
<br>The species does not seem to be important enough as a weed to be considered as a target for biological control.

Source: cabi.org
Title: Juncus tenuis
Description


Tufted or with short vertical rhizome, annual or perennial. Culms terete to somewhat compressed, (occasionally 5) 13-60 cm long, 1.0-2.0 mm (rarely to 3.0 mm) diameter. Stems 20-900 x 0.5-1.5 mm. Leaves all basal, up to 100 mm x 8 mm, usually less than stem, shorter than or occasionally equalling culms;blade flat, 1.5–11 mm wide;auricles absent;sheath pale brown, mostly pink-coloured. Inflorescence terminal, umbel-like and irregularly branched, 2–12 cm long;flowers numerous, 1.5-2.0 mm long, clustered at apex of branches, 5–30 per cluster and 3–20 (rarely to 70) clusters per inflorescence;involucral bract 1, well-developed, to 10 cm long, shorter than inflorescence. Tepals red-brown, mid-rib region often paler or occasionally tepals all straw-brown, with more or less narrow hyaline margins;outer tepals 1.8–2.5 mm long, shorter than or equalling inner tepals;inner tepals often thickened near apex. Stamens 3(-6), shorter than outer tepals;anthers 0.3–0.5 mm long. Capsule longer than or occasionally equalling outer tepals, ellipsoid to narrow-ellipsoid, obtuse to broad-acute, apiculate, golden brown to red-brown, ovoid, mucronate (Moore and Edgar, 1970;Wilson et al., 1993). Pollen grain is monocolpate, circular shape (40.6 mm) with psilate surface (APSA, 2007).

Impact

J. planifolius is a perennial rush plant, which grows exclusively in wetland habitats. It is native to the southern hemisphere but was introduced to the Northern Hemisphere as an ornamental plant. It was first reported on Hawaii in 1930 (Wester, 1992) and was later introduced to Ireland in 1971 (Scannell, 1973, 1975). It has also been introduced to California and Oregon in the USA (USDA-NRCS, 2013).


Source: cabi.org
Title: Lemna minuta
Description

Structurally, the Lemnaceae are the simplest of the flowering plants. The plants are not differentiated into stems and leaves;instead, the plants in the family have an undifferentiated leaf-like body commonly referred to as a frond. Fronds floating, 1 or 2-few, coherent in groups, obovate, flat to thickish (but not gibbous), 0.8-4 mm, 1-2 times as long as wide, margins entire and thin, usually pale green, shining, nearly always with a sharp ridge with white papillae;veins 1, sometimes indistinct, very rarely longer than extension of air spaces, not longer than 2/3 of distance between node and apex;with or without small papillae along midline;anthocyanin absent;largest air spaces much shorter than 0.3 mm;turions absent. Roots to 1.5 cm, tip rounded to pointed, one root per frond;sheath not winged. Stipes (stalks) white, small, often decaying. Flowers within membranous cup-like spathes (open on one side) inside budding pouches located on either side of the basal end. Ovaries 1-ovulate, utricular scale open on 1 side. Fruits 0.6-1 mm, not winged. Seeds with 12-15 distinct ribs (Landolt, 1980;Flora of North America, 2008;Armstrong, 2009).

Impact

L. minuta is a small free-floating plant, no more than 3 mm in length. It is widely distributed in southern and western North America and is also found in Central and South America. It occurs in lowland ditches, ponds, canals, streams and rivers, and more rarely it is found in lakes (Preston and Croft, 1997). It often forms dense mats on the surface of water, reducing the light penetration and gas exchange, often causing the disappearance of submersed aquatic plants. Outbreaks are usually limited in time and space and are favoured by eutrophication. L. minuta is introduced in Eurasia (Landolt 2000) and it was first recorded in western France in 1965. From there it has spread all over Europe as far as southern Russia and Greece. It is also present in Japan (e.g. Landolt, 1986). It is considered a casual alien by Global Compendium of Weeds (2007). In many areas it is a noxious weed, as in Belgium, and it is included in the watch list with moderate impact (Branquart et al., 2007).


Source: cabi.org
Title: Lemna minuta
Host plants Salvinia minima, Lemna Long
Description

S. minima is a deep-green, free-floating, rootless, aquatic fern (ISSG, 2006). Stems can be up to 6 cm and leaves are from 1-1.5 cm long and almost round to elliptic. They are obtuse or notched at the apex and round to heart-shaped at the base. The upward surfaces of the fronds are covered with stiff hairs, with four separated branches. The under surface of the leaves are brown and pubescent with slender and unbranched hairs (Flora of North America Editorial Committee, 1993). The stiff hairs on the fronds serve to trap air, thus providing buoyancy (Dickinson and Miller, 1998). Obscure veins are areolate and do not quite reach to the leaf edges. Sporocarps occur in groups of four to eight, with up to 25 megasporangia (Flora of North America Editorial Committee, 1993).

Recognition

S. minima is free-floating, which makes it easier to identify than most submerged aquatic vegetation. Volunteer monitors should be trained on the identity and habit of this potential invader.

Impact

S. minima is a very productive free-floating, non-rooted aquatic fern native to South and Central America. It was introduced outside its native range in southern Florida, USA in 1926 (USGS, 2005). The plant is degrading wetland ecosystems in several states of the USA (Tipping and Center, 2005). S. minima has an extremely high reproductive potential;the plants can rapidly colonize bodies of water, forming thick mats that displace native species, impact water quality, impede recreational activities, and clog waterways and irrigation channels (Rayachhetry et al., 2002). S. minima is also resistant to desiccation, allowing it to be transported long distances out of water (ISSG, 2006). The species can act as an annual, dying back when temperatures decrease and causing harmful nutrient pulses and dissolved oxygen crashes (Dickinson and Miller, 1998).

Hosts

S. minima is a highly competitive species with a very high growth rate. Colonies of S. minima can grow very densely, such that they shade light from valuable native submerged aquatic plant species (USACE-ERDC, 2002). Dense colonies can thus decrease local biodiversity and degrade the habitat (ISSG, 2006). The plant is also highly competitive among other free-floating species. A competition study specifically showed that S. minima had negative effects on the change in cover of the species Azolla caroliniana and Spirodela punctata (Dickinson and Miller, 1998). In Louisiana, USA native Lemna species were completely replaced by S. minima (ISSG, 2005).


Source: cabi.org
Description

The following description is from Flora of Panama (2016)

Impact

S. linifolia is an herb or small shrub reported as invasive to Cuba and Hawaii, USA (Oviedo Prieto et al., 2012;PIER, 2016). No details are given on its invasiveness or the effects on habitats and/or biodiversity. Although it is listed as invasive for Hawaii by PIER (2016), it also is noted as “not common”.

Hosts

The species occurs as a weed in cultivated land and plantations (Fariñas et al., 2011;JIRCAS, 2016). It is one of the species affected by the Okra Mosaic Virus strain, NIN-OKMV, and could be a source of infection for some crops (Igwegbe, 1983).


Source: cabi.org
Host plants Sida repens, Sida Portal
Title: Sida repens
Description

The following description is from the India Biodiversity Portal (2017)

Impact

Sida repens is a perennial herb native to Central America and parts of South America that grows as a weed in disturbed sites, wastelands, pastures and on roadsides. It has been classified as a weed in Cuba and as invasive in Puerto Rico and the Virgin Islands. This weedy species produces prickly fruits that attach to animal fur or human clothing, facilitating seed dispersal.


Source: cabi.org
Title: Sida repens
Description

T. fragrans is an herbaceous vine, twining, 2-3 m in length. Stems cylindrical, striate, slender, puberulous. Leaves opposite;blades 6.5-11 × 1.8-6 cm, ovate to lanceolate, chartaceous, the apex acute, the base truncate or subcordiform;margins undulate and ciliate;upper surface dark green, glabrous or somewhat scabrous;lower surface pale green, dull, puberulous, with prominent venation;petiole 2-3.5 cm long, slender, pubescent, sulcate, with the base somewhat dilated. Flowers axillary, solitary or in pairs;pedicels pubescent, 5-7 cm long, striate;bracts green, membranaceous, ovate, pubescent, 1.6-2 cm long, covering the calyx. Calyx green, of 15-20 sepals, lanceolate, 3-5 mm long;corolla white, infundibuliform, with 5 lobes, the tube 2.5-4 cm long, narrow at the base, yellow inside, the limb 4-5 cm in diameter. Capsules 1-2.5 cm long, depressed-globose at the base, the upper half in the form of a beak, dehiscent in two halves;seeds 4, globose, approximately 5 mm in diameter, pubescent, with a depression at the base (Acevedo-Rodríguez, 2005). Variation in the shape, size, pubescence, and margin form of the leaves is extensive in T. fragrans, and taxa have been recognized based on these characters (Flora of China Editorial Committee, 2014).

Impact

T. fragrans is an herbaceous fast-growing vine widely cultivated as an ornamental in tropical and subtropical regions of the world, but it is also a common weed in moist disturbed areas, in particular along roadsides (Starr et al., 2003;Randall, 2012). In most cases, this species has been intentionally introduced as an ornamental and it has escaped from cultivation and naturalized in both relatively unaltered and disturbed forests, riversides, roadsides and urban bushland (Starr et al., 2003;Meyer and Lavergne, 2004;Queensland Department of Primary Industries and Fisheries, 2011). T. fragrans is included in the Global Compendium of Weeds where is listed as an “environmental weed,” and it is also listed as invasive in Australia, Japan, Singapore, Cuba, Puerto Rico, Hawaii and French Polynesia among others (Meyer and Lavergne, 2004;Mito and Uesugi, 2004;Chong et al., 2009;Queensland Department of Primary Industries and Fisheries, 2011;Oviedo-Prieto et al., 2012;PIER, 2014).


Source: cabi.org
Description


Perennial, woody vine, 10-20 m in length. Stems are cylindrical, up to 2.5 cm in diameter, striate, puberulous;cross section of the stem with the pith hollow and the xylem tissue with wide rays. Leaves are opposite;blades 15-26 × 13-30 cm, ovate or broadly ovate, chartaceous, the apex acute or acuminate, the base cordiform, the margins lobate-dentate, ciliate;upper surface is dark green, shiny, puberulous, with slightly prominent venation;lower surface is light green, dull, glabrous or puberulous, with prominent venation;petioles 6-12 cm long. Flowers are arranged in axillary cymes;pedicels robust, cylindrical, 4-6 cm long;bracts light green, ovate, approximately 4 cm long, covering the calyx and the corolla tube. The calyx is green with the form of a ring, 4-5 mm long;corolla lilac-blue or white, with 5 lobes, the tube 6-7 cm long, light yellow inside, narrow at the base, the limb 6-7 cm in diameter. Fruits are capsules, approximately 3 cm long, subglobose at the base, the upper half in the form of a beak, explosively dehiscent in two halves (Acevedo-Rodríguez, 2005).

Impact

T. grandiflora is a woody vine included in the Global Compendium of Weeds and it is listed as a very aggressive weed impacting tropical and subtropical ecosystems (Randall, 2012). This species has been repeatedly introduced as an ornamental plant in many countries around the world, but it has become a serious environmental problem when it has escaped from cultivated areas and rapidly colonized natural habitats (ISSG, 2012). The rapid colonization of new habitat by this vine is mainly due to its capability to reproduce sexually by seeds and vegetatively by cuttings, fragments of stems and roots (USDA-NRCS, 2012). Once established, T. grandiflora completely smothers native vegetation by killing host-trees, out-competing understory plants, and negatively affecting the germination and establishment of seedlings of native species (Starr et al., 2003). Currently, T. grandiflora is classified as a “noxious weed” in Australia (Queensland Department of Primary Industries and Fisheries, 2007), and as an invasive species in Central America, the West Indies, Africa, and numerous islands in the Pacific including Hawaii, Fiji, French Polynesia, Palau, and Samoa (see distribution table for details;Acevedo-Rodríguez and Strong, 2012;ISSG, 2012;PIER, 2012).


Source: cabi.org
Description


The following is adapted from Chen and Wu (2003).

Impact

S. urticifolia is a perennial semi-woody herb. It has been grown in gardens for over 200 years. It is a popular ornamental and has been planted in gardens globally because of its attractive blue flowers. It has a very high reproductive rate and in tropical climates the species escapes from cultivation readily. It can form monocultures, invade moist deciduous forests, and interrupt successional processes. It has allelopathic properties that give it the ability to compete with other plant species. The species is highly likely to be transported intentionally to new regions and escape.


Source: cabi.org
Description


The following has been adapted from Flora of China Editorial Committee (2016) and Flora of North America Editorial Committee (2016).

Impact

B. hyssopifolia is an annual herb mostly found in arid and semi-arid habitats. It is native to Eurasia but has been introduced to North America, South America, Hawaii, Australia and parts of Europe. The species can become dominant on alkaline soils where there is little competition from other plant species. It is especially problematic in the southwestern USA, where it is toxic to some livestock, and is readily dispersed as the hooks on ripened fruit attach to animal fur, and it has proven to be a threat to some endangered plant and animal species in the USA.

Biological Control
<br>There is no biological control for B. hyssopifolia (DiTomaso, 2013).

Source: cabi.org
Description


Annual or very rarely biennial, herbaceous, from a stout taproot;stems 15-200 cm tall, erect, glabrous to sparsely tomentose, narrowly and discontinuously winged, the wings spinose, tomentose, branched above the lower third, branches erect to ascending. Basal leaves 6-15 cm long, oblanceolate, deeply 4-10-lobed, the base tapered;cauline leaves alternate, decurrent, sinuate to pinnately lobed, margins spinose, upper surfaces loosely tomentose, becoming glabrous, lower surfaces densely tomentose. Heads discoid (all corollas radial and salverform), 17-22 mm long, 10-20 mm wide, cylindrical to subcylindrical, sessile to stalked, solitary or 2-5 in terminal clusters. Outer phyllaries ovate-lanceolate, loosely tomentose, margins membranous, apices acuminate, terminating in a straight spine;inner phyllaries narrower, scarious. Corollas 10-14 mm long, pink to rose-purple, sometimes white. Achenes 4-6 mm long, tan to brown, sometimes shiny, transversely wrinkled, tubercled above;pappus 10-20 mm long, composed of flat, minutely barbed, white bristles. (Description slightly modified from Wilken and Hannah, 1998).

Impact

Carduus pycnocephalus is a thistle that is native to the Mediterranean region and some other countries further north or east. It has been introduced, presumably accidentally, to the USA, Australia, New Zealand and some other countries in Europe, Asia, Africa and South America. In many of the countries where it has become naturalized it is regarded as a legally-defined noxious plant or pest plant, depending on the current terminology;it also causes problems in some countries where it is considered a native species. It can form dense infestations in some places where it can smother other, smaller plants and, where it occurs in grazed pastures, can limit the access of livestock and also cause them physical damage, as well as contaminating wool. In this way it has become a problem in the USA, Australia, New Zealand, Pakistan, Iran and Europe (Pitcher and Russo, 1988).

Hosts


Pasture species can be replaced, their growth inhibited and accessibility to grazing livestock obstructed by high populations of C. pycnocephalus rosettes and flowering plants (Kelly and Popay, 1985).

Biological Control
<br>According to Picher and Russo (1988) all major parts of C. pycnocephalus are damaged by one or more insect species in southern Europe, whereas in southern California the thistles are relatively free of insect damage. The seed head weevil Rhinocyllus conicus [or Curculio conicus ] has been introduced into several countries (Canada, USA, Australia, New Zealand) for control of one or more thistle species, including C. pycnocephalus. The larvae feed on the receptacle and developing achenes of thistle species and certainly destroy many seeds, but often enough survive to maintain populations of thistles (Popay et al., 1984;Pitcher and Russo, 1988). A crown weevil (Trichosirocalus horridus [or Ceutorhynchus horridus ]) has also been introduced to several countries as a biocontrol agent for thistle species and may be effective against C. pycnocephalus.<br>The fungal rust Puccinia cardui-pycnocephali [ P. calcitrapae ], already present in many countries where C. pycnocephalus or C. tenuifolius or both are present, has also been considered as a possible biocontrol agent, but its effects seem less than lethal although more virulent strains may be more damaging (Olivieri, 1984).

Source: cabi.org
Description

P. pilosa is an annual or rarely short-lived perennial, succulent, prostrate to erect herb to 30 cm tall;roots fibrous to slightly fleshy;leaves fleshy, opposite or alternate, to 20 mm long, 3 mm wide, terete to hemispheric, linear to oblong-lanceolate, with conspicuous axillary hairs 1-18 mm long;flowers subtended by involucre of dense wool and 6-9 bracts, flowers mostly 5-12 mm wide, petals 5, dark pink-purple, stamens 5-12 or more, red, stigmas 3-6 lobed;capsules ovoid, to 4.3 mm, seeds black to gray, sometimes purplish, orbiculate, 0.5-0.7 mm in diameter.

Impact

Portulaca pilosa is a fleshy-leaved annual or short-lived perennial with low, sprawling growth habit. It is a weed throughout its range. It is thought to have originated in South America but its native range is uncertain. It occurs from South America north to the Caribbean and the southern USA, and is also found growing on some Pacific islands, Australia and parts of Asia, and perhaps Africa. This self-compatible species has a short life cycle with the ability to produce mature seed in less than two months. A single plant can produce nearly 300,000 seeds annually. The species has a high drought tolerance, and throughout its range it is predominantly a weed of disturbed dry soils. It is often found in coastal ecosystems such as dunes and rocky shores. It competes with native herbs in these habitats, including some endangered species and narrow endemics.

Hosts


Although P. pilosa has a broad global range, it is not generally considered a problematic agricultural weed, despite its preference for disturbed soils. In the USA it is described as a common weed of one or more crops in Louisiana, Alabama, Georgia, South Carolina, North Carolina and Puerto Rico (Invasive.org, 2015).


Source: cabi.org
Host plants Aedes albopictus Long
Description

Adults are known as tiger mosquitoes due to their conspicuous patterns of very black bodies with white stripes. Also, there is a distinctive single white band (stripe) down the length of the back. The body length is about 3/16-inch long. Like all mosquitoes, Asian tiger mosquitoes are small, fragile insects with slender bodies, one pair of narrow wings, and three pairs of long, slender legs. They have an elongate proboscis with which the female bites and feeds on blood.

Impact

The Asian tiger mosquito is spread via the international tyre trade (due to the rainwater retained in the tyres when stored outside). In order to control its spread such trading routes must be highlighted for the introduction of sterilisation or quarantine measures. The tiger mosquito is associated with the transmission of many human diseases, including the viruses: Dengue, West Nile and Japanese Encephalitis.


Source: cabi.org
Description

Culex quinquefasciatus is a medium-sized (approx. 4 mm) mosquito, predominately golden brown in coloration with solid coloured legs and a characteristic white-banded abdomen. The original type specimen collected from the Mississippi River in the southern United States by Thomas Say was lost but type specimens from C.R.W. Wiedemann’s 1828 description of Culex fatigans = quinquefasciatus still exist in the Naturhistorisches Museum of Vienna. A contemporary specimen of Cx. quinquefasciatus from New Orleans has since been designated as a neotype (Belkin, 1977).

Recognition


Surveillance for Cx. quinquefasciatus generally consists of dip surveys of all suspect larval habitats and selective trapping of adults using mechanized gravid traps baited with infusions of grass, manure or other organic matter (Reiter, 1983). Larval mosquitoes are often identified using morphological keys focused on chaetotaxy - the structure and arrangement of setae - of the siphon and terminal segments of the abdomen (Belkin, 1962;for more current terminology see Harbach and Knight (1980, 1981)). Morphological distinction of Cx. quinquefasciatus from related species is difficult at best but a number of rapid molecular diagnostic assays have been developed (Crabtree et al., 1995;Aspen and Savage, 2003;Smith and Fonseca, 2004).

Impact

Culex quinquefasciatus is a peridomestic mosquito seldom found far from human residence or activity, and readily feeds on avian, mammalian or human hosts. The larvae are typically found in the eutrophic water of artificial containers or man-made impoundments including open ponds, ditches and drains containing human or animal sewage. As such, Culex quinquefasciatus was uniquely adapted to the environs of historical sailing ships outfitted for long voyages where polluted water and livestock were common. Since adult mosquitoes can fly short distances to shore (Subra, 1981;LaPointe, 2008) and immature forms could be carried ashore in water casks taken to be refilled (Hardy, 1960), it is likely that this mosquito was spread worldwide by commercial sailing vessels involved in the Atlantic slave trade, Old China trade and American whale oil industry between the 17 and 19 th centuries (Lounibos, 2002). Today, adult Cx. quinquefasciatus are among the most commonly intercepted mosquitoes in passenger airline cabins and their larvae can still be found in exposed cargo (tyres and heavy equipment) and containers on modern ships (Joyce, 1961;Smith and Carter, 1984;Scholte, 2010).


Source: cabi.org
Description


Recent molecular analysis has shown that Acanthaster planci is in fact a species complex consisting of four distinct clades from the Red Sea, the Pacific, the Northern and the Southern Indian Ocean. Benzie (1999) had previously demonstrated the genetic differentiation between A. planci from the Pacific and the Indian Ocean, and this genetic grouping is reflected in the distribution of colour morphs: grey-green to red-brown in the Pacific Ocean, and blue to pale red in the Indian Ocean (Benzie, 1999). Colour combinations can vary from purplish-blue with red tipped spines to green with yellow-tipped spines (Moran, 1997). Those on the Great Barrier Reef are normally brown or reddish grey with red-tipped spines, while those in Thailand are a brilliant purple (Moran, 1997). Adult A. planci usually range in diameter from around 20 to 30cm (PERSGA/ GEF 2003) although specimens of up to 60cm (and even 80cm) in total diameter have been collected (Chesher, 1969;Moran, 1997). The juvenile starfish begins with 5 arms and develops into an adult with an astounding 16 to 20 arms, all heavily armed with poisonous spines 4 to 5cm in length, which can inflict painful wounds (Moran, 1997;Birk, 1979). Arm values vary between localities with a range of 14 to 18cm given for the Great Barrier Reef (Moran 1997). Starfish are usually concealed during daylight hours, hiding in crevices (Brikeland and Lucas, 1990;Chesher, 1969). Groups of starfish often move as huge masses of 20 to 200 individuals, presenting a terrifying "front" which destroys the reef as it moves through (Chesher, 1969). Signs of starfish presence are obvious;the coral skeleton is left behind as the result of starfish feeding and stands out sharply as patches of pure white, which eventually become overgrown with algae (Chesher, 1969). In some cases, herbivorous sea urchins move in to feed on algae, creating a pattern against the white coral that resembles the holes of swiss cheese (Tsuda et al. 1970).

Impact


Coral gardens from Micronesia and Polynesia provide valuable marine resources for local communities and environments for native marine species such as marine fish. In coral ecosystems already affected by coral bleaching, excess tourism and natural events such as storms and El Nino, the effects of the invasive crown-of-thorns starfish (Acanthaster planci) on native coral communities contributes to an already dire state of affairs. Acanthaster planci significantly threatens the viability of these fragile coral ecosystems, and damage to coral gardens by the starfish has been quite extensive in some reef systems. Outbreaks in the Pacific appear to be more massive and widespread than those elsewhere. This may reflect different patterns of outbreak between Pacific and Indian Ocean populations, which have recently been shown to form separate clades of an A. planci species complex. (Vogler et al. 2008;and see 'Description' section).


Source: cabi.org
Description

Eggs
The yellow or pale-orange, elongate-oval eggs, are ca 1.2 mm long. They are laid in groups of 12-25 on the underside of potato leaves. The females glue them to the leaf by one end using a special secretion. The long axis of the egg is almost perpendicular to the leaf. Eggs within a mass tend to form irregular rows and hatch simultaneously.
Larvae
Body strongly convex dorsally, with large abdomen. Head, bearing 6 ocelli behind the antenna on each side and a pair of 5-dentate mandibles. Three thoracic segments, each bearing a pair of 3-segmented legs, plus claw. Abdomen 9-segmented. Colour changing with development, first instar cherry-red with shiny, black head and legs;later instars becoming progressively carrot-red, then pale orange in final instar.
Head, legs and posterior part of pronotum black to deep brown;two conspicuous rows of dark spots occur on the lateral aspects of the mesothoracic and abdominal segments 1 to 7, the uppermost surrounding the spiracles, and also segments 8 and 9 with dark dorsal plates. Setae when present are very small, some occur on the head, legs, pronotum, on the pigmented areas and ventrally. Spiracles small, annular with black peritremes and situated on the mesothorax and first 8 abdominal segments. Body length of full-grown larva about 15 mm.
A detailed generic diagnosis of Leptinotarsa larvae is provided by Cox (1982) and the first instar is described by Peterson (1951). The weights of the four larval instars are given by Balachowsky (1963).
Pupae
Yellowish, bearing short setae on low, conical, brown tubercles. Head bearing several short setae, mandibles apically unidentate. Thorax with pronotum bearing about 100 setae;meso- and metathorax much more sparsely setose;apices of femora bearing about 3-5 setae and apical tarsal segment 1 seta. Abdominal segments 1-6 with lateral expansion dorsal to spiracle, dorsally bearing about 48 short setae, laterally about 9 setae on large papilla ventral to spiracle. Apical abdominal segment bearing a single, brown, median, sharply-pointed urogomphus or spine. Spiracles situated on mesothorax and abdominal segments 1-8;peritremes dark brown, but pale on abdominal segments 6-8. For further details, see Cox (1996).
Adults
Head, pronotum and venter yellow-orange with black markings, legs and scutellum orange-yellow, elytra yellow-orange with five longitudinal black stripes. Apical segment of maxillary palpi cylindrical, rounded apically, shorter than preceding segment. Elytra punctate-striate, epipleura glabrous. Mesosternum not raised above level of prosternum. Profemora normal, third tarsal segment entire, tarsal claws simple, divergent, not fused basally. Body length 8.5-11.5 mm.
The genus was revised by Jacques (1988). A key to the North American species is given by Wilcox (1972) and Jacques (1985).

Recognition


Adults and larvae are easily seen because of their large size. L. decemlineata has a tendency to release its hold on plants that are shaken and this characteristic can be used to detect insects hidden among foliage. Visual sampling of potato fields was as efficient for estimating population density as the whole-plant bag-sampling method, and more efficient than sweep netting (Senanayake and Holliday, 1988). Soil sampling at harvest for buried beetles in diapause provides reliable results in area surveys (Glez, 1983). A sequential sampling plan has been reported for estimating populations of Colorado potato beetle egg masses and of adults and larvae (Hamilton et al., 1997a).

Impact


Colorado beetle principally attacks an introduced field crop grown as a monoculture, but not to an extent that has affected the area of the crop grown. It is not accordingly invasive in the usual environmental sense. It has no effects on the environment.

Hosts

L. decemlineata attacks potatoes and various other cultivated crops including tomatoes and aubergines. It also attacks wild solanaceous plants, which occur widely and can act as a reservoir for infestation. The adults feed on the tubers of host plants in addition to the leaves, stems and growing points.


Source: cabi.org
Host plants Liriomyza trifolii
Description


Descriptions of L. trifolii refer to fresh materials. Dry specimens may be distorted due to the manner in which they have been preserved. Also, the age of the specimen, when killed, will have some effect on its preservation characteristics.
For accurate identification, examination of the leaf mine and all stages of development are crucial.
Egg
L. trifolii eggs are 0.2-0.3 mm x 0.1-0.15 mm, off white and slightly translucent.
Larva
This is a legless maggot with no separate head capsule, transparent when newly hatched but colouring up to a yellow-orange in later instars and is up to 3 mm long. L. trifolii larvae and puparia have a pair of posterior spiracles terminating in three cone-like appendages. Spencer (1973) describes distinguishing features of the larvae. Petitt (1990) describes a method of identifying the different instars of the larvae of L. sativae, which can be adapted for use with the other Liriomyza species, including L. trifolii.
Puparium
This is oval and slightly flattened ventrally, 1.3-2.3 x 0.5-0.75 mm with variable colour, pale yellow-orange, darkening to golden-brown. The puparium has posterior spiracles on a pronounced conical projection, each with three distinct bulbs, two of which are elongate. Pupariation occurs outside the leaf, in the soil beneath the plant.
Menken and Ulenberg (1986) describe a method of distinguishing L. trifolii from L. bryoniae, L. huidobrensis, and L. sativae using allozyme variation patterns as revealed by gel electrophoresis.
Adult
L. trifolii is very small: 1-1.3 mm body length, up to 1.7 mm in female with wings 1.3-1.7 mm. The mesonotum is grey-black with a yellow blotch at the hind-corners. The scutellum is bright yellow;the face, frons and third antennal segment are bright yellow. Male and female L. trifolii are generally similar in appearance.
L. trifolii are not very active fliers, and in crops showing active mining, the flies may be seen walking rapidly over the leaves with only short jerky flights to adjacent leaves.
Head
The frons, which projects very slightly above the eye, is just less than 1.5 times the width of the eye (viewed from above). There are two equal ors and two ori (the lower one weaker). Orbital setulae are sparse and reclinate. The jowls are deep (almost 0.33 times the height of the eye at the rear);the cheeks form a distinct ring below the eye. The third antennal segment is small, round and noticeably pubescent, but not excessively so (vte and vti are both on a yellow ground).
Mesonotum
Acrostical bristles occur irregularly in 3-4 rows at the front, reducing to two rows behind. There is a conspicuous yellow patch at each hind-corner. The pleura are yellow;the meso- and sterno-pleura have variable black markings.
Wing
Length 1.3 -1.7 mm, discal cell small. The last section is M(sub)3+4 from 3-4 times the length of the penultimate one.
Genitalia
The shape of the distiphallus is fairly distinctive but could be mis-identified for L. sativae. Identification using the male genitalia should only be undertaken by specialists.
Colour
The head (including the antenna and face) is bright yellow. The hind margin of the eye is largely yellow, vte and vti always on yellow ground.
The mesopleura is predominantly yellow, with a variable dark area, from a slim grey bar along the base to extensive darkening reaching higher up the front margin than the back margin. The sternopleura is largely filled by a black triangle, but always with bright yellow above.
The femora and coxa are bright yellow, with the tibia and tarsi darker;brownish-yellow on the fore-legs, brownish-black on the hind legs. The abdomen is largely black but the tergites are variably yellow, particularly at the sides. The squamae are yellowish, with a dark margin and fringe.
Although individual specimens may vary considerably in colour, the basic pattern is consistent.

Recognition

L. trifolii are small black and yellow flies which may be detected flying closely around host plants or moving erratically and rapidly upon the leaf surfaces. Inspection of the leaf surface will reveal punctures of the epidermis and the obvious greenish-white mines with linear grains of frass along their length. For accurate identification, examination of the leaf mine and all stages of development are crucial.
L. trifolii larvae will be found feeding at the end of the mine, or the mine will end with a small convex slit in the epidermis where the larva has left the mine to pupariate on the ground. Sometimes the puparium may be found adhering to the leaf surface, although in most cases the fully-fed larva will have found its way to the ground beneath the plant to pupariate. This is especially true in hot, dry conditions where the larva/puparia would quickly desiccate if exposed on the leaf surface. Empty puparial cases are split at the anterior end, but the head capsule is not usually separated from the rest of the case.
Mined leaves should be collected into polythene bags and transferred to a press as soon as possible. Leaves containing larvae intended for breeding should be collected into individual polythene bags, which on return to the laboratory should be slightly over-pressurized by blowing into them before sealing the end. Blowing up the bag by mouth and sealing it adds valuable carbon dioxide to the moist air mix. Constant attention is required to ensure that puparia are transferred to individual tubes until the fly emerges. If the plant material begins rotting, good material with feeding larvae must be removed to more sanitary conditions.
When puparia are observed they can be very carefully removed to tubes containing a layer of fine sand, or a small strip of blotting paper or filter paper. This should be kept damp (never wet) until the adult emerges.
On emergence, the fly should be kept for at least 24 hours to harden up. Do not allow condensation to come into contact with the fly, or it will stick to the water film and be damaged.
Field collection of the adult L. trifolii is done by netting. The use of sticky traps, especially yellow ones, placed near host plants is a very effective method of collection and estimation of infestation.
If the puparial stage is collected from the soil, care must be taken not to damage the puparial skin or death will almost certainly follow. The pupae should be stored in glass tubes on a layer of clean sand or, better still, thick filter paper. The tube must have high humidity, but be free of condensation.
When the fly emerges, it must be allowed to harden for 24 hours before killing for identification purposes. Ensure that the tube has no condensation present.
Newly emerged adult L. trifolii are generally softer than specimens aged for several days and may crinkle as drying proceeds, especially the head. The ptilinal sac may still protrude from the suture between the frons and face obliterating some important characteristics. Adults should be dried slowly in the dark in a sealed receptacle over blotting paper. If preserving wet is preferred, the live specimen should be dropped into 20-40% alcohol, and transferred to 70-90% alcohol after 2 days.

Symptons

L. trifolii feeding punctures appear as white speckles between 0.13 and 0.15 mm in diameter. Oviposition punctures are usually smaller (0.05 mm) and are more uniformly round.
L. trifolii leaf mines can vary in form with the host plant, but when adequate leaf area is available they are usually long, linear, narrow and not greatly widening towards the end. They are usually greenish white.
In very small leaves the limited area for feeding results in the formation of a secondary blotch at the end of the mine, before pupariation. In Kenya, Spencer (1985) notes the growth of many L. trifolii from mines which began with a conspicuous spiral. This is not a characteristic associated with L. trifolii on other continents.
The frass is distinctive in being deposited in black strips alternately at either side of the mine (like L. sativae), but becomes more granular towards the end of the mine (unlike L. sativae) (Spencer, 1973).
Fungal destruction of the leaf may also occur as a result of infection introduced by L. trifolii from other sources during breeding activity. Wilt may occur, especially in seedlings.

Hosts


The host range of L. trifolii includes over 400 species of plants in 28 families including both ornamental crops (Bogran, 2006) and vegetables (Cheri, 2012). The main host families and species include: Apiaceae (A. graveolens);Asteraceae (Aster spp., Chrysanthemum spp., Gerbera spp., Dahlia spp., Ixeris stolonifera, Lactuca sativa, Lactuca spp., Zinnia spp.);Brassicaceae (Brassica spp.);Caryophyllaceae (Gypsophila spp.);Chenopodiaceae (Spinacia oleracea, Beta vulgaris);Cucurbitaceae (Cucumis spp., Cucurbita spp.);Fabaceae (Glycine max, Medicago sativa, Phaseolus vulgaris, Pisum sativum, Pisum spp., Trifolium spp., Vicia faba);Liliaceae (A. cepa, Allium sativum) and Solanaceae (Capsicum annuum, Capsicum frutescens, Petunia spp., Solanum lycopersicum, Solanum spp.) (EFSA, 2012).
It is now considered to be the most important pest of cowpea (Vigna uniguilata), towel gourd (Luffa cylindrica), cucumber (Cucumis sativus) and many other vegetable crops in southern China (Gao, 2014). In Europe, L. trifolii is a major pest of lettuce, beans, cucumber and celery, Capsicum sp., carnations, clover, Gerbera sp., Gypsophila sp., lucerne, Senecio hybridus, potatoes and tomatoes (EFSA, 2012). It is now a major pest of the Compositae worldwide, particularly chrysanthemums (including Dendranthenum, the commercial 'Mum') in North America, Colombia, and elsewhere. It also causes severe damage to different open field crops, such as chili peppers in Mexico.


Source: cabi.org
Host plants Ceratitis rosa
Description

C. rosa, like other Ceratitis spp., has banded wings, and a swollen scutellum which is marked yellow and black. The pattern of grey flecks in the basal wing cells distinguishes Ceratitis spp. from most other genera of tephritids.

Recognition

C. rosa can be monitored by traps baited with male lures. Like Ceratitis capitata, and members of subgenera Ceratitis and Pterandrus in general, it is attracted to trimedlure and terpinyl acetate, but not methyl eugenol or cue lure. It is also very sensitive to enriched ginger oil (EGO) lure (Mwatawala et al., 2015;Manrakhan et al., 2017). The responses to baits of 16 Ceratitis species were tabulated by Hancock (1987).
Trimedlure (t-butyl 4(or 5) chloro-2-methyl cyclohexane carboxylate) is the most widely used lure for C. capitata and the following information could also be relevant for C. rosa. The history of trimedlure development and the problems of isolating the best of the eight possible isomers was discussed by Cunningham (1989). The lure is usually placed on a cottonwool wick suspended in the middle of a plastic trap that has small openings at both ends. Suitable traps were described by White and Elson-Harris (1994). Lure can either be mixed with an insecticide or a piece of paper dipped in insecticide can be placed in the trap. Traps are usually placed in fruit trees at a height of ca. 2 m above ground and should be emptied regularly as it is possible to catch hundreds of flies in a single trap left for just a few days, although the lure may remain effective for a few weeks.
A detailed study of trap position effects was carried out by Israely et al. (1997). A review of the biological aspects of male lures was presented by Cunningham (1989) and the use of lures was described more fully by Drew (1982). A trapping system used to monitor for possible introductions of C. capitata into New Zealand has been described by Somerfield (1989) and should also be effective for C. rosa. The possibility of the development of pheromone based trapping systems was discussed by Landolt and Heath (1996) and it may be possible to extend that approach to C. rosa. Trapping efficiency of C. capitata is also enhanced by the use of fluorescent colours, particularly light green (Epsky et al., 1996). This may also apply to C. rosa.
Recent comparative research on attraction sensitivity of C. rosa by using different lures, has shown that enriched ginger oil (EGO) lure is an effective attractant for C. rosa (Manrakhan et al., 2017) and can actually be a more sensitive attractant than trimedlure (Mwatawala et al., 2015).

Impact

C. rosa is a polyphagous African species. Its known distribution is mainly southern and eastern Africa. It is considered to be a major pest of a number of commercial fruits, including fruits that are grown in subtropical or more temperate environments (but see remark under host plants). It has similar environmental requirements to Ceratitis capitata except that it can withstand less dry conditions. It should be considered as a potential invasive species in other parts of Africa, outside its current range, and in other parts of the world (Tanga et al., 2018). The most likely pathway of dispersal and introduction is as larvae in infested fruits with commercial shipments or in the luggage of travellers. C. rosa is of quarantine significance for EPPO, JUNAC and OIRSA.

Hosts

C. rosa is a polyphagous species. The list of known host plants for C. rosa as given by De Meyer et al. (2002) and at http://projects.bebif.be/fruitfly/index.html is based on records of C. rosa s.l. and thus can refer to either C. rosa, C. quilicii, or both. Detailed analysis, based on rearing experiments, is required to establish the exact host range of C. rosa. Transport of any of the host fruits could result in dispersal and distribution, if infested with fruit fly larvae.


Source: cabi.org
Description


Cytoplasmic inclusion bodies typical of other caulimoviruses have been reported in the vascular parenchyma and mesophyll cells of infected plants (Kaname, 1975;Kitajima et al., 1973;Frazier and Converse, 1980;Morris et al., 1980). Isolated virions ca 50 nm in diameter were also found in phloem parenchyma cells of symptomatic Fragaria vesca indicator clones (Fránová-Honetslegrová et al., 1999). Native viral DNA is circular and double-stranded with two single-stranded discontinuities (Stenger et al., 1988). It contains 7876 nucleotides (Petrzik et al., 1998b). Seven open reading frames potentially code for proteins of 37.8;18.3;16.6;56.0;81.1;59.0 and 12.6 kDa.

Recognition


Visual examination of the symptoms of SVBV on commercial cultivars on strawberry is not reliable.

Symptons


Clear banding pattern along main and secondary veins is induced on F. vesca clones if SVBV is present alone in host plants. Usually SVBV occurs in strawberries in a complex with other diseases, which mask or intensify the vein banding pattern (Frazier and Morris, 1987).
Symptoms initially appear on the youngest developing leaf;there is epinasty of midribs and petioles, a tendency for opposite halves of leaflets to be appressed, irregular, wavy leaflet margins, and slight crinkling of the laminae. Usually, these symptoms are mild and are not all present simultaneously. It is not until the affected leaf expands that clearing, followed by yellowish banding of some or all of the veins, becomes visible. Often, this coloration occurs in scattered discontinuous streaks of varying lengths along the main and secondary veins.
The second and third leaves formed after symptom onset are affected more severely than the first or any subsequent leaf;in older leaves, chlorotic streaks are reduced in number, scattered and confined to portions of the leaflets. This may be followed by the appearance of a series of apparently healthy leaves and then reappearance of mild or severe symptoms (Frazier, 1955;Mellor and Fitzpatrick, 1961;Miller and Frazier, 1970;Smith, 1972).
On commercial strawberries, there are no very diagnostic symptoms but, if strawberry latent C disease is also present, the reaction to infection is intermediate to that on Fragaria vesca (EPPO/ CABI, 1996). In cv. Marshall, for example, the veinbanding is usually diffuse, commonly located along the main veins and may often appear as spots. As affected leaves mature, the veinbanded areas may gradually disappear, or they may become brownish-red or necrotic. On outdoor plants especially, the veins become discoloured, without previous chlorosis. Affected leaflets characteristically exhibit epinasty, mild crinkling and wavy margins.
SVBV usually does not induce distinct symptoms in commercial cultivars, and often the only indications of infection are loss of vigour, stunting, lowered yields, and general 'running out' of a cultivar. SVBV rarely occurs singly in strawberry;frequently several viruses are present, and together they cause more severe reductions of productivity and fruit quality (Spiegel and Martin, 1998).

Hosts


SVBV is known to occur only on species of Fragaria. The main host is Fragaria vesca (wild strawberry). Commercial strawberries may also be infected, but diagnostic symptoms are usually only apparent when Strawberry latent C virus is present simultaneously (EPPO/ CABI, 1996). The garden burnet (Sanguisorba minor) has been established as a symptomless experimental host by graft inoculation and by the dark strawberry aphid vector Chaetosiphon jacobi (Mullin et al., 1980).


Source: cabi.org
Description

Eggs
The eggs are cemented to the surface of pulses and are smooth, domed structures with oval, flat bases.
Larva and Pupa
The larvae and pupae are normally only found in cells bored within the seeds of pulses. For descriptions and a key including C. maculatus larvae, see Prevett (1971) and Vats (1974).
Adult
C. maculatus adults are 2.0-3.5 mm long. The antennae of both sexes are slightly serrate (for details of antennal and sensilla structure see Mbata et al. (1997)). Females often have strong markings on the elytra consisting of two large lateral dark patches mid-way along the elytra and smaller patches at the anterior and posterior ends, leaving a paler brown cross-shaped area covering the rest. The males are much less distinctly marked. In common with other species of Callosobruchus, C. maculatus has a pair of distinct ridges (inner and outer) on the ventral side of each hind femur, and each ridge bears a tooth near the apical end. The inner tooth is triangular, and equal to (or slightly longer than) the outer tooth. A unique chordotonal structure in the fore coxae of adult C. maculatus and C. subinnotatus was described by Ramaswamy and Monroe (1997). The location and ultrastructure of sex pheromone glands in female C. maculatus is described by Pierre et al. (1996).
Several workers have described an active- or flight-form of adult C. maculatus which is apparently more active and is more strongly marked, with a white pygidium (Utida, 1953). The function of this form, which appears in populations as a result of genetic and environmental factors, is not understood.

Recognition


No particular detection or inspection methods for Callosobruchus spp. have been developed.
The potential exists for the development of population monitoring by use of sex pheromones. The female-produced sex pheromone has been isolated and identified (Phillips et al., 1996);and the behavioural and electroantennogram (EAG) response to pheremonal components by males was recorded by Shu et al. (1996).

Hosts

C. maculatus is a major pest of cowpeas, green gram and lentils. For a complete list of host plants, see Udayagiri and Wadhi (1989), and Desroches et al. (1997). Host plants vary considerably in their suitability for larval development (Wijeratne, 1998). Alpha-amylase inhibitors prevent development of C. maculatus on a number of legumes (Blanco-Labra et al., 1996;Reis et al., 1997;Ishimoto et al., 1999;Janarthanan et al., 1999) including Phaseolus vulgaris, but not the development of the bruchids Acanthoscelides obtectus and Zabrotes subfasciatus (Ishimoto and Chrispeels, 1996).
There have been many studies of host preference in C. maculatus and its ability to adapt to using hosts less suitable for larval development, for example Huignard et al. (1996);Taheri (1996);Sulehrie et al. (1998). Inheritance of aspects of host plant choice were observed by Messina and Slade (1997).


Source: cabi.org
Description

Eggs
The eggs are cemented to the surface of pulses and are smooth, domed structures with oval, flat bases.
Larva and Pupa
The larvae and pupae are normally only found in cells bored within the seeds of pulses. For a description and key to larvae of Callosobruchus spp., see Vats (1974).
Adult
C. chinensis adults are 2.0-3.5 mm long. The antennae are pectinate in the male, and serrate in the female. The elytra are pale brown, with small median dark marks and larger posterior dark patches, which may merge to make the entire posterior part of the elytra dark in colour. The side margins of the abdomen have distinct patches of coarse white setae, a feature that is shared with C. rhodesianus and C. theobromae. In common with other species of Callosobruchus, C. chinensis has a pair of distinct ridges (inner and outer) on the ventral side of each hind femur, and each ridge has a tooth near the apical end. The inner tooth is slender, rather parallel-sided, and equal to (or slightly longer than) the outer tooth.
Variations in morphological parameters may be induced by different host densities, whether development occurs in pods or in loose seeds (Nahdy et al., 1995), or by population source (George and Verma, 1997).

Recognition


No particular detection or inspection methods for Callosobruchus spp. have been developed.
The potential exists for the development of population monitoring by use of sex pheromones. The existence of a female sex pheromone in C. chinensis was demonstrated by Honda and Yamamoto (1976), and Gharib et al. (1992), but the pheromone is not commercially available (Phillips, 1994;Plarre, 1998).

Hosts

C. chinensis is a major pest of chickpeas (Pandey and Singh, 1997), lentils, green gram, broad beans, soybean (Srinivasacharyulu and Yadav, 1997;Yongxue et al., 1998a) adzuki bean and cowpeas in various tropical regions. It also attacks other pulses on occasions, but appears to be incapable of developing on common beans (Phaseolus vulgaris).
See Udayagiri and Wadhi (1989) for a full list of host plants.


Source: cabi.org
Host plants Liriomyza cicerina
Description

Adult

Impact

There is no evidence of the species being invasive in the regions and countries where it is present. L. cicerina is not on the alert lists of either the International Union for Conservation of Nature (IUCN) or the Invasive Species Specialist Group (ISSG). It is not listed as a regulated species by EPPO in the ‘Action A1/A2 Lists of pests recommended for regulation’ for any of the countries of its occurrence. Its host specialization to only a few plants from the Fabaceae family, the climatic limitations and the great numbers of naturally-occurring parasitoids are some of the factors that prevent the species from becoming an invasive. There are no data about any major introductions of any economic importance.

Hosts

The host plants of L. cicerina are only from the Fabaceae family: Cicer arietinum (chickpea) (Hering, 1957;Spencer, 1973);Hymenocarpus circinnatus (disc trefoil) (Hering, 1957);Melilotus alba (white sweet clover);Melilotus officinalis (yellow sweetclover) (Robbins, 1983);Ononis species, including Ononis arvensis (field restharrow) (BMNH), Ononis hircine (Hering, 1957), Ononis repens (common restharrow) (Hering, 1957), Ononis spinosa (spiny restharrow) (Hering, 1957). There is new record of L. cicerina found as a pest of faba bean (Vicia faba) at Damnhour region in Egypt (El-Serwy, 2003). Spencer (1973) suggested that the primary host plants are likely to be the European plant Ononis spp. because he assumed the centre of origin of L. cicerina to be in Europe. Since chickpea was introduced from India he supposed that a host switch to Cicer was established in Europe. However, recently L. c icerina was confirmed from India (Naresh and Malik, 1989). It is unknown whether or not
Host Plants and Other Plants Affected
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Plant name|Family|Context
Cicer arietinum (chickpea)|Fabaceae
Hymenocarpus circinnatus|Fabaceae
Melilotus albus (honey clover)|Fabaceae
Melilotus officinalis (yellow sweet clover)|Fabaceae
Ononis|
Ononis repens|Fabaceae
Ononis spinosa|Fabaceae
Vicia faba (faba bean)|Fabaceae
Growth Stages
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Flowering stage, Fruiting stage, Seedling stage, Vegetative growing stage
Symptoms
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L. cicerina damages the host plant in two ways;females puncture the plants to feed before ovipositing, but the more serious damage is caused by the larvae, mining the leaves (Lahmar and Zeouienne, 1990). The adult females puncture the upper surface of chickpea leaflets with their ovipositor and feed on the exudates from these, which causes a stipple pattern on the leaflets. In some of the feeding punctures, eggs are inserted just under the epidermis (Weigand, 1990a). The leafminer larvae feed in the leaf mesophyll tissue forming a serpentine mine that later becomes a blotch. The mining activity of the larvae reduces the photosynthetic capacity of the plant and heavy infestation may cause desiccation and premature fall of leaves (Weigand, 1990a). In his original description of this species in 1875, Rondani wrote: “Larva mining the leaves of C. arietinum, frequently causing substantial damage” (Spencer, 1973). Shevtchenko (1937) recorded that mined leaves turned yellow, dry up and many fall prematurely. Lower leaves were attacked first and often only three or four healthy leaves remained on each stem. L. cicerina was found quite common in all the surveyed chickpea fields in Syria (Sithanantham and Reed, 1980), attacking the spring-sown crop more severely than the winter-sown crop and varieties with large leaflets more than those with small leaflets.
List of Symptoms/Signs
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Sign|Life Stages|Type
Leaves / internal feeding
Leaves / wilting
Leaves / yellowed or dead
Whole plant / early senescence
Biology and Ecology
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Shevtchenko (1937) made a detailed study of this species in Ukraine. He found that there could be as many as four generations between April and August. Adults emerge from overwintering pupae as temperatures increase at the beginning of Spring. In Slovakia, adults of the hibernating populations emerged in May;the next emergence was in July. Part of this generation completed its life cycle in mid-August and disappeared;the other part remained in diapauses during the winter and completed its life cycle the following Spring (Pastucha, 1996). In Romania, the pest had three to four generations per year and larvae were present throughout the vegetative period (Banita et al., 1992). In a much warmer climate (Morocco), the date of emergence varied between years, but in a single year, most L. cicerina emerged within a week, with little difference between geographical areas (Lahmar and Zeouienne, 1990). In 1983, the time between the first appearance of adults in the fields and the first larval damage was 12 days. In Turkey, Hincal et al. (1996a) reported that the adults of L. cicerina emerged in the second half of April and the first half of May, when average temperature was 9.0-14.3 o C and the ground temperature was 19.2-21.2 o C. The larvae appeared 3 to 20 days after adult emergence when the plants were 5-10 cm high. There were two peaks in the population density of the leafminer: one at the end of May;and the second at the end of June. According to Shevtchenko (1937), the egg stage lasts for 2-3 days, and 42% of the leaves contain a single egg, 45% - two, 9% - three, 2% - four and 2% - five eggs. The larval mine is on the upper or lower surface of the leaf and is linear, shallow, at first greenish, later whitish, winding irregularly and frequently forming a secondary blotch. The life cycle is completed in between 20 and 30 days, the pupal stage lasting generally from 10-12 days in the early generation. Under the conditions of Morocco, the development time of the first generation was only 25 days and was followed by three overlapping generations before the Summer diapauses in July (Lahmar and Zeouienne, 1990). Pupation takes place externally (Spencer, 1976). Shevtchenko (1937) found up to 59 puparia per sq. dm 1.10 -1, the equivalent of 1852 per m 2. Del Canizo (1934) has studied the species in Spain where the main areas of cultivation of Cicer arietinum are Castille, Estramadura and Andalucia and he has confirmed the very large populations frequently present in the early generation when fields of chickpea can be seen with scarcely a single plant unaffected. Environmental Requirements Judging from the distribution, L. cicerina prefers arid, semi-arid and temperate (especially Mediterranean) climate conditions. Higher humidity and higher irrigation levels cause increase of the leafminer population density (Cikman and Civelek, 2006).
Climate
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Climate|Status|Description|Remark
Aw - Tropical wet and dry savanna climate| Tolerated
60mm precipitation driest month (in winter) and (100 - [total annual precipitation{mm}/25])
B - Dry (arid and semi-arid)| Preferred
860mm precipitation annually
BS - Steppe climate| Preferred
430mm and 860mm annual precipitation
BW - Desert climate| Preferred
430mm annual precipitation
C - Temperate/Mesothermal climate| Preferred
Average temp. of coldest month 0°C and 18°C, mean warmest month 10°C
Cf - Warm temperate climate, wet all year| Preferred
Warm average temp. 10°C, Cold average temp. 0°C, wet all year
Cs - Warm temperate climate with dry summer| Preferred
Warm average temp. 10°C, Cold average temp. 0°C, dry summers
Cw - Warm temperate climate with dry winter| Tolerated
Warm temperate climate with dry winter (Warm average temp. 10°C, Cold average temp. 0°C, dry winters)
D - Continental/Microthermal climate| Tolerated
Continental/Microthermal climate (Average temp. of coldest month 0°C, mean warmest month 10°C)
Ds - Continental climate with dry summer| Tolerated
Continental climate with dry summer (Warm average temp. 10°C, coldest month 0°C, dry summers)
Latitude/Altitude Ranges
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Latitude North (°N)|Latitude South (°S)|Altitude Lower (m)|Altitude Upper (m)
65
25
0
0
Rainfall
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Parameter|Lower limit|Upper limit|Description
Mean annual rainfall|430|1500|mm;lower/upper limits
Natural enemies
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Natural enemy|Type|Life stages|Specificity|References|Biological control in|Biological control on
Dacnusa cicerina| Parasite
Larvae| to species
Tormos et al.,
2008
Diaulinopsis arenaria| Parasite
Larvae| to species
Cickman et al.,
2008
Diglyphus crassinervis| Parasite
Larvae| to species
Cikman et al.,
2008
Diglyphus isaea| Parasite
Larvae| to species
Weigand and Tahhan,
1990
Neochrysocharis ambitiosa| Parasite
Larvae| to species
Cickman et al.,
2008
Neochrysocharis formosa| Parasite
Larvae| to species
Cikman et al.,
2008
Neochrysocharis sericea| Parasite
Larvae| to species
Cickman et al.,
2008
Opius monilicornis| Parasite
Larvae| to species
Cikman et al.,
2008
Opius pygmaeus| Parasite
Larvae| to species
Canizo LDel,
1934
Opius tersus| Parasite
Larvae| to species
Cickman et al.,
2008
Pediobius acantha| Parasite
Larvae/Pupae| to species
Gencer,
2004
Pediobius metallicus| Parasite
Larvae/Pupae| to species
Cikman et al.,
2008
Notes on Natural Enemies
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Parasites A braconid in Spain was found to parasitize up to 90% of larvae of the first generation of L. cicerina on chickpea, thus effectively reducing populations later in the year (Del Canizo, 1934). The identity of this species is not certain, but it is possibly Opius pygmaeus, which has been confirmed parasitizing L. cicerina in Surrey, England (Fischer, 1972). In more recent studies, again in Spain, Garrido et al. (1992) found the parasitoid Opius monilicornis and Tormos et al. (2008) found Dacnusa cicerina sp. n. Eurytoma sp. is reported as a possible hyperparasitoid of D. cicerina. A comparison is made between the larvae and the adults of several Dacnusa species (Tormos et al., 2008): the adults of D. cicerina are similar to those of Dacnusa rodriguezi. The immature larvae are similar to those of Dacnusa areolaris and Dacnusa dryas, and the mature larvae are very similar to those of D. dryas, from which they differ in having scale-like sensilla on the thorax and abdomen. The venom apparatus is very similar to that of Dacnusa flavicoxa, differing from it in length of the reservoir and the number of gland filaments. The mature larva of Eurytoma illiger has well-differentiated pleural and ventral setae. In Morocco, O. monilicornis was identified (Lahmar and Zeouienne, 1990). Hincal et al. (1996b) reported O. monilicornis in chickpea fields in the region of Izmir, Denizil and Usak, Turkey in 1991-1994. In a study of the parasitoids on Agromyzidae pests in cultivated and non-cultivated areas in Turkey among which L. cicerina was included, a total of six parasitoids from Braconidae and 12 parasitoids from Eulophidae (Hymenoptera) were registered (Cikman and Uygun, 2003). It is not clear which parasitoid parasitizes which host. Later, in the region of Sanhurfa, Turkey, Cikman et al. (2008) found a total of eight parasitoid species on L. cicerina on chickpea: the braconids O. monilicornis and Opius tersus;and the eulophids Diaulinopsis arenaria, Neochrysocharis formosa, Diglyphus crassinervis, Neochrysocharis ambitiosa, Neochrysocharis sericea and Pediobius metallicus. In Ankara province, Gencer (2004) found only one parasitoid attacking larvae and pupae of L. cicerina – Pediobius acantha. Sithanantham and Reed (1980) established that many of the collected larvae and pupae in chickpea fields in Syria were parasitized, but no information was given about the species. Later Weigand (1990a) reported two parasitoids on L. cicerina in Syria: Diglyphus isaea and Opius monilicornis, and El-Bouhssini et al. (2008) reported the parasitoid O. monilicornis. D. isaea has been reported for the first time from Tehran and West Azerbaijan as a parasitoid of L. cicerina (Adldoost, 1995). Several parasitoids are mentioned as present in faba bean fields at Damnhour, Sids and El-Zarka in Egypt on L. cicerina, Liriomyza bryoniae and Liriomyza sativae: D. isaea;Hemiptarsenus zilahisebessi;Chrysonotomyia sp.;Pnigalio sp.;Opius sp.;and Cirrospilus sp. (El-Serwy, 2003). No data is given on which of the parasitoids have emerged from L. cicerina. In Romania, Banita et al. (1992) established the rate of parasitism of L. cicerina in chickpea crops, in Dolj district.
Pathway Causes
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Cause|Notes|Long Distance|Local|References
Crop production|| Yes
Yes
Spencer,
1973
Plant Trade
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Plant parts liable to carry the pest in trade/transport|Pest stages|Borne internally|Borne externally|Visibility of pest or symptoms
Growing medium accompanying plants
pupae| Yes
Pest or symptoms usually visible to the naked eye
Leaves
eggs;larvae| Yes
Pest or symptoms usually visible to the naked eye
Seedlings/Micropropagated plants
eggs;larvae| Yes
Pest or symptoms usually visible to the naked eye
Impact Summary
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Category|Impact
Economic/livelihood
Negative
Economic Impact
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Cicer arietinum (Kabuli chickpea) grown on about 10 million ha, is the world’s third most important pulse crop (Rheenen, 1991). Kabuli chickpea is important not only as a source of human food, but is also a valuable fodder crop. In the Mediterranean region the chickpea leafminer, mainly L. cicerina, but also Phytomyza lathyri, is the main insect pest occurring in several countries in high densities every year (Weigand, 1990a). In the arid and semi-arid conditions of this region, L. cicerina is listed among the most stressing factors for chickpea growth together with Ascochyta blight (Ascochyta rabiei), and cold (Singh and Jana, 1993). In a report on the cultivation of chickpea in Spain (Govantes and Montanes, 1982), it is mentioned that L. cicerina is the most important pest of the culture. Del Canizo (1934) refers to fields of chickpeas in Spain in which virtually all plants show evidence of leaf-mining attack. The plants were not destroyed, but substantially weakened, with a consequent reduction of yield. Damage to the leaves actively facilitates subsequent fungal attack, referred to locally as “la rabia”, caused by Phyllosticta rabiei. Shevtchenko (1937) refers to the fungal disease in Ukraine as “Ascochyta”. Some economic loss, both in the pea harvest and in foliage for fodder, undoubtedly occurs wherever this crop is cultivated (Del Canizo, 1934). It can be assumed that the mass outbreak that occurred in Ukraine in 1934 was exceptional, but nevertheless L. cicerina must be considered as a major pest, liable at any time when a significant build up of population occurs, to cause serious damage. In a review of the insect pests of faba, lentils, and chickpea in North Africa and West Asia, Cardona (1983) listed L. cicerina and Heliothis spp. as the most important pests of chickpea in the field. In Turkey, in a study of the Agromizid fauna in Sanliurfa province, L. cicerina was found to be seriously damaging cultivated plants together with Liriomyza trifolii (Cikman and Uygun, 2003). In Syria, L. cicerina was found to be quite common in all the surveyed chickpea fields (Sithanantham and Reed, 1980) and Hariri and Tahhan (1983a) pointed out Heliothis armigera, Heliothis viriplaca and L. cicerina as the most economically important pests of chickpea. In another publication, the same authors (Hariri and Tahhan, 1983b) also added Callososbruchus chinensis in addition to these pests. A survey of the damage caused to chickpea in Syria and Jordan carried out in May 1983 (Sithanantham and Cardona, 1984) showed that the damaged caused by L. cicerina was greatest in Northern Syria. The damage caused by L. cicerina was estimated by Weigand (1990a) as serious, reaching up to 30% of seed yield loss. The attacks of L. cicerina, although considered less serious than in spring, are strong enough to cause considerable losses in case of drought at the beginning of the cycle in the south part of Morocco (Kamel, 1990). In India, the major pest problems in chickpea are the pod borer (Helicoverpa armigera and Helicoverpa punctigera), the leafminer L. cicerina, the cutworm Agrotis ipsilon, aphids (Aphis craccivora), semilooper (Autographa nigristigna) and bruchids (Callosobruchus spp.) (Sharma et al., 2007). A study in Romania in 1986-1990 established that about two-thirds of the pest fauna in chickpea crops in the Dolj district comprised of L. cicerina (Banita et al., 1992). The attack was maximal during pod formation and the losses of the leaf mass reached 31-86%. In former Czechoslovakia, L. cicerina was first found in 1988 (Kolesik and Pasticha, 1992) in the region of Borovce and in the next 2 years large infestations were recorded. There are also results showing no significant impact of L. cicerina on the yield. In Slovakia, Pastucha (1996) reported 41% mined leaves from the first generation of the fly and 85% from the second generation. Although quite high, the percentage of the mined leaves did not influence yield, but reduced seed weight. A study on the populations of L. cicerina on eight chickpea cultivars in Turkey in Sanliurfa province showed that there were very minor differences in yield among them, and there was no correlation found between larval density and yield loss (Cikman and Civelek, 2007). A survey in three regions in Turkey (Yozgat, Konya and Eskisehir), showed that L. cicerina and thrips were the most widespread pests of chickpea, but were not economically important (Tamer et al., 1998).
Risk and Impact Factors
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Invasiveness
Has a broad native range
Abundant in its native range
Fast growing
Impact outcomes
Host damage
Increases vulnerability to invasions
Negatively impacts agriculture
Likelihood of entry/control
Highly likely to be transported internationally accidentally
Uses List
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General
Laboratory use
Research model
Prevention and Control
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Due to the variable regulations around (de)registration of pesticides, your national list of registered pesticides or relevant authority should be consulted to determine which products are legally allowed for use in your country when considering chemical control. Pesticides should always be used in a lawful manner, consistent with the product's label.
Control
Cultural control and sanitary measures The effect of planting date on chickpea leafminer infestation along with other items was studied in Aleppo, Syria (El-Bouhssini et al., 2008). Chickpea (Cicer arietinum) planted in Spring had a significantly higher number of damaged leaflets than the winter-sown crop. There were a significantly higher number of damaged leaflets on the local cultivar, as compared with an improved variety (Flip 82-150, ‘Ghab 3’) in both planting dates and both years. For the spring and winter cultivars, there were 1183 and 320 damaged leaflets, respectively, for the local cultivar and 968 and 244 for Ghab 3 in 1998;i.e. a nearly four-fold increase in the number of damaged leaflets between Winter and Spring planting. This study shows that chickpea leafminer could be effectively managed by integrating different pest management options such as winter sowing and use of tolerant cultivars. El-Serwy (2003) is suggesting several agricultural practices i.e. deep ploughing and applying kerosene as control measures against pupae of the leafminer. Higher irrigation levels caused increase of the population density of the leafminer, but on the other hand, yield was higher too (Cikman and Civelek, 2006). Based on the results, highest irrigation levels are recommended in the Sanhurfa province in Turkey. Physical/mechanical control Yellow, moistened traps were more effective in capturing adults than Tullgren funnels or net sweeps (Banita et al., 1992). El-Serwy (2003) tested the effect of spreading the harvested plants on plastic sheets to facilitate collection of the accumulated leafminer pupae. Biological control In most seasons, the populations of L. cicerina are effectively controlled by its parasites. A braconid in Spain was found to parasitize up to 90% of larvae of the first generation of L. cicerina on chickpea, thus effectively reducing populations later in the year (Del Canizo, 1934). In more recent studies, again in Spain, Garrido et al. (1992) found the parasitoid Opius monilicornis and Tormos et al. (2008) found Dacnusa cicerina sp.n. Eurytoma sp. was reported as a possible hyperparasitoid of D. cicerina. In Morocco, O. monilicornis was identified (Lahmar and Zeouienne, 1990). The braconid parasitoids in general were described as the most important natural enemies of L. cicerina, parasitizing 20-35% of the first generation of the leafminer. Hincal et al. (1996b) studied the rate of parasitism of L. cicerina larvae by O. monilicornis in chickpea fields in the region of Izmir, Denizil and Usak, Turkey in 1991-1994. They found that in May and June, parasitism in Izmir was 0-23.91%, 0-29.82% in Denizil and 0-28.33% in Usak. In a study of the parasitoids on Agromyzidae pests in cultivated and non-cultivated areas in Turkey, among which L. cicerina was included, a total of six parasitoids from Braconidae and 12 parasitoids from Eulophidae (Hymenoptera) were registered (Cikman and Uygun, 2003). Later, in the region of Sanhurfa, Turkey, Cikman et al. (2008) found a total of eight parasitoid species only on L. cicerina on chickpea. Leaves with mines were sampled weekly and kept in the laboratory to observe the emerging parasitoids. The braconids O. monilicornis and Opius tersus, and the eulophids Diaulinopsis arenaria and Neochrysocharis formosa occurred both during the Winter and the Summer seasons. Diglyphus crassinervis, Neochrysocharis ambitiosa, Neochrysocharis sericea and Pediobius metallicus occurred only in the Summer growing areas. D. arenaria was the predominant parasitoid with 4-7.7% parasitism rate whereas N. ambitiosa and O. monilicornis were the second and third most predominant species. The results of these trials show that because D. arenaria occurs throughout every season in Turkey, it could potentially be used for control of L. cicerina. Sithanantham and Reed (1980) established that many of the collected larvae and pupae in chickpea fields in Syria were parasitized, but no information is given about the species. Later Weigand (1990a) and Weigand and Tahhan (1990) reported two parasitoids on L. cicerina: Diglyphus isaea and O. monilicornis, and El-Bouhssini et al. (2008) reported the parasitoid O. monilicornis. Several parasitoids are mentioned as present in faba bean fields at Damnhour, Sids and El-Zarka in Egypt on L. cicerina, Liriomyza bryoniae and Liriomyza sativae: D. isaea;Hemiptarsenus zilahisebessi;Chrysonotomyia sp.;Pnigalio sp.;Opius sp.;and Cirrospilus sp. (El-Serwy, 2003). No data is given on which of the parasitoids have emerged from L. cicerina. Synchronization was found between the time of host emergence and the abundance of the larval parasitoid D. isaea in the active season, but not in the diapause season. Asynchrony was observed between the larval-pupal parasitoid Opius sp. and the leaf-mining flies. The population growth rates of larval parasitoids were lower than those of the flies, which retarded the biological control, particularly at the beginning of the season. In Romania, Banita et al. (1992) established the rate of parasitism of L. cicerina in chickpea crops, in Dolj district, and according to the authors it was low;not exceeding 3-4%. Application of insecticides inevitably reduces the population density of the parasitoids and hence, their efficacy. The population of the parasitoid O. monilicornis on L. cicerina on chickpea in Syria was significantly reduced by treatments with deltamethrin compared to treatments with neem oil or the control (El-Bouhssini et al., 2008). In their study, Cikman and Kaplan (2008) established that treatments with azadirachtin influence the rate of parasitism less than treatments with cyromazine. The rate of parasitism in the experimental plots was 35.08-31.64% and 16.98-18.18%, respectively. The insecticidal efficacy of aqueous and methanol extracts from fruits of the Chinaberry tree, Melia azedarach was tested against the chickpea leafminer in Syria (Al-Housari et al., 2003). The results revealed that both extracts significantly reduced the mean percent of the leaflet damage and feeding punctures at all concentrations compared with the control. The highest concentration of methanol extract (2%) gave the highest reduction in percent leaflet damage. No phytotoxicity was observed on treated plants. The insecticidal effect of different seed extract levels (1, 2, 3 and 4 kg seeds/10 litres water) of the same plant (M. azedarach) on the larvae of L. cicerina was investigated at Usak and Denizil-Tavas, Turkey (Hincal et al., 2000). The larvae were counted on 25 damaged leaves in each plot. The seed extract level of 3 and 4 kg seed/10 litres water was effective against the larvae of L. cicerina for 15 days when both adults and larvae were present. Cikman et al. (2008) investigated the effect of Bacillus thuringiensis on L. cicerina in the chickpea growing region of Sanlurfa, Turkey. B. thuringiensis was applied at a concentration of 60 x 106/mg B. thuringiensis spores. It was applied at the recommended rate of 75g/100 litres water. Application dates were chosen when the pest density reached a level of two to three larvae/leaf in 50% of the plants in the field, which is the economic threshold. The leaves were sampled weekly from treated (with cyromazine and B. thuringiensis) and control plots and kept in the laboratory under observation to compare the number of emerging leafminer adults and their parasitoids. Both cyromazine and B. thuringiensis reduce the number of the leafminer compared to the control. There was no difference between cyromazine and B. thuringiensis treated plots for average number of adults and larvae. The percentage of parasitism in the B. thuringiensis -treated plots was higher than in cyromazine-treated plots and was 37.70-35.08% and 15.79-13-33%, respectively. A commercial neem insecticide was compared with cyromazine for its efficacy against L. cicerina (Cikman and Kaplan, 2008). Field trials were carried out from March to June 2006-2007 in chickpea-growing areas of Sanliurfa, Turkey. Azadirachtin was applied at a concentration of 1% (NeemAzl T/S 0.01% A.I.). For comparison, cyromazine 75% (Cyrogard 75 WP) was applied at the recommended rate of 20g/100 litres water. There was no difference between azadirachtin A and cyromazine treated plots for average yield. Chemical control In 1990 in Syria, a recommendation was given for application of Nuvacron or Thiodan at flowering (Weigand, 1990a). However, the use of insecticides may not be either practical or economical for the small farm holders in the region. In a study in 1986-1990, Banita et al. (1992) established that various chemicals applied at commencement of pod formation substantially reduced infestation of L. cicerina and increased yield, especially Trigard (cyromazine), Thiodan (endosulfan) and Fastac (alpha-cypermethrin). El-Bouhssini et al. (2008) tested the efficacy of deltamethrin and neem oil against L. cicerina and their influence on the parasitoids. Both neem oil and deltamethrin significantly reduced leaflet damage in the two cultivars tested. However, deltamethrin significantly reduced the number of adult parasitoids compared with the unsprayed control and neem oil treated for the Spring-sown chickpea. Host Resistance Although the breeding history of C. arietinum is short, considerable progress has been made in cultivar improvement (Rheenen, 1991). Breeding cultivars with resistance to freezing, Fusarium oxysporum f. sp. ciceris, Ascochyta rabiei and Helicoverpa armigera, and for short duration, are examples of successes. Yield stability has increased and yield gains of 1.6% per annum have been achieved. In the West Asia and Mediterranean regions, drought avoidance by Winter sowing has been achieved by incorporating disease resistance and changing the sowing date. This has resulted in a 75% yield increase. A 20% yield increase was recorded in Peninsular India because of the extra-short duration. Desirable traits include resistance to high temperature, salinity, Botrytis cinerea, Sclerotinium rolfsii, L. cicerina and stunt caused by bean leaf roll luteovirus. Attention should also be given to the problems of chilling and lodging in the most productive chickpea-growing areas. The possibility of applying new biotechnological methods for genetic improvement, particularly the use of interspecific crossing, micropropagation, somaclonal variation, and isoenzyme and RFLP mapping, are discussed. The main approach for chickpea integrated control in Syria is screening for resistance to L. cicerina (Weigand, 1990b). In 1991, a catalogue of kabuli chickpea germplasm was published (Singh et al., 1991), presenting data on the evaluation of 6330 Winter-sown accessions of resistance to eight biotic and abiotic stresses (Ascochyta rabiei, Fusarium oxysporum f. sp. ciceris, L. cicerina, Callososbruchus chinensis, Heterodera ciceri, cold, herbicides and iron deficiency). Lists were provided of passport information (donor and origin) and evaluation data (24 descriptors) for each accession. Two hundred accessions of wild Cicer species were evaluated for resistance to L. cicerina in Aleppo, Syria (Singh and Weigand, 1995). Accessions were screened under natural insect infestation in the field in March-June along with a susceptible control line (C. arietinum ICL482). Two accessions of Cicer cuneatum (ILWC40 and ILWC 187) and 10 accessions of Cicer judaicum (all ILWC lines) were rated as 2 on a scale of 1-9, where 1 = free from any damage and 9 = maximum damage. Another 18 lines of C. judaicum, four of Cicer pinnatifidum and one of Cicer reticulatum were rated as 3 (resistant). Three species were incompatible in crossing with chickpea, but C. reticulatum is being used in a breeding programme. Seeds from one leafminer (L. cicerina) resistant line (ILC5901) were exposed to 40, 50 and 60 kR (Omar and Singh, 1995). The M 1 generation was sown at Tel Hadya, Syria during Winter. Germination was reduced at high dosages. Survival to maturity was drastically reduced especially after the 60 kR treatment. The percentage of sterile plants was highest at a dosage of 40 kR g rays. The parental lines and the M 1 generation were grown in 1993. Of the 3292 progenies harvested from the M 1, three were very early, six were early, 295 were medium and the remaining 2994 were late to very late in maturity. The six early plants were harvested individually;seeds from five of the six produced early maturing progeny. None of them segregated for maturity or any other observable character. All of these early mutants produced a higher seed yield than the parental lines and resistance to ascochyta blight or leafminer. Singh et al. (1998) evaluated data on 228 accessions of eight annual wild Cicer species and 20 cultivated chickpea check lines for diversity in response to six of the most serious biotic and abiotic stresses that reduce crop yield and production stability of chickpea, i.e. ascochyta blight (A. rabiei), fusarium wilt (F. oxysporum f. s. ciceris), leafminer L. cicerina, bruchid C. chinensis, cyst nematode H. ciceri and cold. Relative frequencies of score reactions to the above six stresses were recorded from all the annual wild Cicer species and the cultivated taxon. Patterns of distribution and amount of variation of the resistance reactions differed between stresses and species. Cicer bijugum, Cicer pinnatifidum and Cicer echinospermum showed accessions with at least one source of resistance (1 to 4 score reactions) to each stress. Overall, C. bijugum showed the highest frequencies of the highest categories of resistance. Next in performance was C. pinnatifidum followed by C. judaicum, C. reticulatum and C. echinospermum. Furthermore, C. bijugum had the highest number of accessions with multiple resistance to the six stresses: two accessions were resistant to five stresses and 16 to four. According to Shannon-Weaver diversity indices (H’), five species showed discrete mean diversity indices that varied from 0.649 in C. pinnatifidum to 0.526 in C. judaicum, whereas Cicer chorassanicum, Cicer cuneatum and Cicer yamashitae showed the lowest H’ values, which were 0.119, 0.174 and 0.216, respectively. Pair-wise correlation among the six biotic and abiotic stresses showed the possibility of combining these resistances. Interestingly, multiple resistant accessions were predominantly of Turkish origin. The International Center for Agricultural Research in the Dry Areas (ICARDA) screened 6025 germplasm lines of chickpea for resistance to L. cicerina (Singh and Weigand, 1996). ILC3800 and ILC7738 (PI58039 to PI587041, respectively) were consistently rated resistant (3 on a scale of 1 [free from insect damage] to 9 [severe mining on almost all leaflets]) and 30% defo


Source: cabi.org
Description

T. minutum is an extremely small, inconspicuous, drab brown, soft-bodied ant in the subfamily Dolichoderinae (Hymenoptera: Formicidae). The following characters can be used to diagnose it from all known invasive and introduced ants. Total length ca. 1.5 mm. Head width ≤0.45 mm. Antenna 12-segmented. Antennal scape length less than 1.5x head length. Eyes medium to large (greater than 5 facets), do not break outline of head in full-face view. Antennal sockets and posterior clypeal margin separated by a distance less than the minimum width of antennal scape. Anterior margin of clypeus distinctly concave. Mandible with distinct break in tooth size after fourth tooth dorsum of mesosoma with metanotal groove, but never with a deep and broad concavity;lacking erect hairs. Propodeum with dorsal surface distinctly shorter than posterior face;lacking posteriorly projecting protrusion. Waist 1-segmented (may be hidden by gaster). Petiolar node appearing flattened. Gaster armed with ventral slit;with four plates on its dorsal surface and with the fifth plate on the ventral surface. Distinct constriction not visible between abdominal segments 3+4. Hairs not long, thick and produced in pairs. Uniformly light to dark brown, often with paler brownish yellow appendages.

Impact

T. minutum is a very small (1.5 mm), inconspicuous, drab brown, soft-bodied ant that occurs in Australia and Oceania. The species is widely considered native across this region, but it is possible that part of its current range resulted from anthropogenic dispersal. The species is most commonly found foraging and nesting in disturbed forest vegetation, but is also known to occur on the ground and in primary forest. Although little is known about the biology of T. minutum and it is not on any alert or pest lists, the species has been implicated in the decline of two endangered butterfly species endemic to Micronesia, primarily through the predation of eggs and larvae. T. minutum belongs to a taxonomically difficult species-complex that requires additional study before any of the known populations can be conclusively considered invasive. The species is rarely reported from quarantine interceptions and is unlikely to pose a significant invasion risk.


Source: cabi.org
Description

Solenopsis papuana are very small monomorphic ants. They have a light reddish yellow to medium reddish brown colouration. The total length of workers is around 1-2mm. Antennae are 10-segmented with a 2-segmented club. Eyes are small to medium in size and contain less than 10 ommatidia. The mandibles can have 4 or 5 teeth. The head is subquadrate, and is longer than it is wide. The metanotal groove of this species is distinct and the petiole is higher than the postpetiole. All the dorsal surfaces of S. papuana have erect setae. The gaster is oval with the first segment longer than half the total length (Harris et al. 2005).

Recognition


The Pacific Invasive Ant Key (PIAKey) manual Pacific Invasive Ants Taxonomy Workshop Manual can both be used in identifying invasive ants in the Pacific region.

Impact

Solenopsis papuana is a native ant of the Pacific region that thrives in the company of other more major invasive ants, but is not a major pest species on its own. It has been introduced to Hawaii and has been able to invade intact forest land.


Source: cabi.org
Description

L. neglectus was only described in 1990 from a population in Budapest, Hungary (Van Loon et al., 1990). It is a member of the sub-family Formicinae. The length of the worker, queen and male are 2.5-3mm (worker), 5.5-6mm (queen), 2.5mm (male);the mandibles are 7-toothed;hairs are lacking on the scape (first segment of antenna) and usually on the legs. Their colour is yellowish-brown with the thorax somewhat paler. The live weight of the worker is 0.65-0.80mg and the queen, 6.8-9.6mg. Espadaler and Bernal (2004) observed that "the female is immediately recognisable within the European Lasius by its comparatively reduced size and proportionately smaller gaster (swollen part of abdomen), as compared with the thorax. The male is the smallest within the European Lasius (s.str.) species".

Impact

Lasius neglectus, known as the invasive garden ant, is a recent arrival in Europe from the Middle East, first recognised in Hungary in 1990. Some populations have attained pest status but at other sites, the ant is still in an arrested state, perhaps in the lag-phase lacking the major characteristics of invaders. Negative effects are reported in buildings, where the ants are a nuisance to residents, a pest in food preparation areas and cause damage to electrical installations, and also where high numbers of ants tend aphids on trees producing quantities of honey dew and the ensuing sooty mould. There is some evidence that native ant species have been displaced.


Source: cabi.org
Host plants Dieback
Description

S. vayssierei is the only known hypogeal (below-ground) species in the family Stictococcidae (Tindo et al., 2006). It is a Sternorrhynchan with incomplete metamorphosis. Ngeve (2003a) described the males as rare and the more common adult female as dark-red, circular and flattened. In contrast, Tindo et al. (2006) described the adult females as brown and the first and second instars as purple-red.

Symptons

Young feeder roots of germinating cassava cuttings are attacked by both the nymphs and adults of S. vayssierei. The feeding damage causes premature leaf-fall, wilting, tip dieback and ultimately results in death. Those plants that are not attacked until later develop normally and tuberize, however, they exhibit small mature tuberous roots and become covered in scales, making them unsuitable for sale (Ngeve, 2003a).

Hosts

S. vayssierei feeds on the root system of cassava (Manihot esculenta), affecting tuber formation of the plant (Williams et al., 2010);however, there is evidence to suggest either polyphagy or involvement of more than a single scale species (Tindo et al., 2006). Sixteen plant species belonging to 13 families have been identified as hosts of S. vayssierei in the Congo basin (Tindo et al., 2009;see Host Plants/Crops Affected), but this may reflect the involvement of more than one species, as yet unidentified. It is thought that native Dioscorea species may play an important role in maintaining Stictococcus populations during long fallows and in secondary and primary forests. Cassava, an exotic plant in this area, may contribute to the growth of S. vayssierei in fallows less than 8 years old (Tindo et al., 2009).

Biological Control
According to Ngeve (2003b), biological control agents such as endomycorrhizae should be studied to determine their usefulness in pest control in Cameroon farming conditions.

Source: cabi.org
Host plants