Effects

Q&A

Effects
Description

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

Hosts

M. jalapa is reported as being a weed in apple orchards (CONABIO, 2016). Its allelopathic effects can inhibit the germination and growth of wheat and cabbage (Xu et al., 2008).


Source: cabi.org
Effects
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
Description


Eggs
The eggs of G. rostochiensis are always retained within the cyst body and no egg sacs are produced. The eggshell surface is smooth and no microvilli are present.
Length=101-104 µm;width="46"-48 µm;L/W ratio=2.1-2.5
Females
The females emerge from the root cortex about one month to six weeks after invasion by the second-stage juveniles. They are pure white initially, turning golden yellow on maturation. Mature females are approximately 500 µm in circumference without a cone. The cuticle of the female sometimes has a thin subcrystalline layer.
Stylet length=23 µm ± 1 µm;stylet base to dorsal oesophageal gland duct=6 µm ± 1 µm;head width at the base=5.2 µm ± 0.7 µm;head tip to median bulb=73 µm ± 14.6 µm;median bulb valve to excretory pore=65 µm ± 2.0 µm;head tip to excretory pore=145 µm ± 17 µm;mean diameter of the median bulb=30µm ± 3.0 µm;mean diameter of the vulval basin=22 µm ± 2.8 µm;vulval slit length=9.7 µm ± 2.0 µm;anus to vulval basin=60 µm ± 10 µm;number of cuticular ridges between the anus and vulva=21 ± 3.0.
The female head bears one to two annules and the neck region has numerous tubercules, which can be seen using a scanning electron microscope. The head skeleton is hexaradiate and weak. The stylet is divided equally in length between the conus and the shaft. An important diagnostic feature is the backward slope of the stylet knobs. The median bulb is large and circular and well developed. The large paired ovaries often displace the oesophageal glands. The excretory pore is well defined at the base of the neck. The posterior of the female, at the opposite pole to the neck and head, is referred to as the vulval basin and is contained within a rounded depression. The vulval slit is located in the centre of this region flanked on either side by papillae, which usually fill the translucent areas of cuticle in crescentic shape, from the slit to the edge of the fenestra. The anus is distinct and is often seen at the point in the cuticle where the 'V' shape tapers to an end. The number of cuticular ridges found in the area between the anus and the edge of the fenestra is counted as an aid to identification of Globodera species. The entire cuticle is covered in small subsurface punctations.
Cyst
Length without neck=445 µm ± 50 µm;width="382" µm ± 60 µm;neck length=104 µm ± 19 µm;mean fenestral diameter=19.0 µm ± 2.0 µm;anus to fenestra=66.5 µm ± 10.3 µm;Granek's ratio=3.6 ± 0.8.
Cysts contain the eggs, the progeny for the next generation, and are formed from the hardened dead cuticle of the female. Newly produced cysts may still show an intact vulval basin but older cysts, particularly those which have been in the soil for many seasons, will have lost all signs of their genitalia with only a hole in the cuticle to show the position of the fenestral basin.
Males
Length=0.89 -1.27 mm;width at excretory pore=28 µm ± 1.7 µm;head width at base=11.8 µm ± 0.6 µm;head length=7.0 µm ± 0.3 µm;stylet length=26 µm ± 1.0 µm;stylet base to dorsal oesophageal gland duct=5.3 µm ± 1.0 µm;head tip to median bulb valve=98.5 µm ± 7.4 µm;median bulb valve to excretory pore=74 µm ± 9µm;head tip to excretory pore=172 µm ± 12.0 µm;tail length=5.4 µm ± 1.0 µm;tail width at anus=13.5 µm ± 0.4 µm;spicule length=35.0 µm ± 3.0 µm;gubernaculum length=10.3 µm ± 1.5µm.
The male is vermiform in shape with a short tail and no bursa. On fixation, the body assumes a curved shape with the posterior region twisted at a 90 degree angle to the remainder of the body. There are four incisures in the mid-body i.e. three bands which terminate on the tail. The rounded head is offset and bears 6-7 annules. The head is strongly developed having a hexaradiate skeleton. The cephalids are located at body annules 2-4 and 6-9, respectively. The stylet is strong and has backward sloping knobs. The median bulb is well developed and has a large crescentic valve. The nerve ring is located around the oesophagus between the median bulb and the intestine. The hemizonid is found 2-3 annules anterior to the excretory pore and is itself two annules in length. The hemizonion is approximately nine body annules posterior to the excretory pore and is one annule in length. The single testis fills half the body cavity. The paired spicules are arcuate and end with single tips. The gubernaculum is around 10 µm in length and 2 µm in thickness and lies in a position dorsal to the spicules.
Juveniles
Body length=468 µm ± 100 µm;width at excretory pore=18 µm ± 0.6 µm;head length=4.6µm ± 0.6 µm;stylet length=22 µm ± 0.7 µm;head tip to median bulb valve=69 µm ± 2.0 µm;median bulb valve to excretory pore=31 µm ± 2.0 µm;head tip to excretory pore=100 µm ± 2.0 µm;tail length=44 µm ± 12 µm;tail width at anus=11.4 µm ± 0.6 µm;hyaline tail length=26.5 µm ± 2.0 µm.
The second-stage juvenile hatches from the egg, the first moult taking place within the egg. The juvenile, like the male, is vermiform with a rounded head and finely tapered tail. The hyaline portion of the tail represents about two thirds of its length. The lateral field has four incisures in the mid-body region reducing to three at the tail terminus and anterior end. The head is slightly offset and bears four to six annules. The head skeleton is well developed and hexaradiate in form. The cephalids are located at body annules 2-3 and 6-8, respectively. The stylet is strong, the conus being about 45% of the total length. The stylet knobs are an important diagnostic feature and typically slope backwards. The median bulb is well developed and elliptical in shape, having a large central valve. The nerve ring encircles the oesophagus between the median valve and the intestine. The hemizonion is about one body annule in width and is located five body annules posterior from the excretory pore. The hemizonid is around two body annules in width and is found just anterior to the excretory pore. The gonad primordium is four-celled and located at around 60% of the body length.
Other measurements can be found in Granek (1955), Spears (1968), Green (1971), Greet (1972), Golden and Ellington (1972), Hesling (1973, 1974), Mulvey (1973), Behrens (1975), Mulvey and Golden (1983), Othman et al. (1988) and Baldwin and Mundo-Ocampo (1991).

Recognition


Potato cyst nematodes, in common with other cyst nematodes, do not cause specific symptoms of infestation. Initially, crops will display patches of poor growth and these plants may show chlorosis and wilting. When the tubers are harvested there will be a yield loss and tubers will be smaller. To be confident that these symptoms are caused by potato cyst nematodes and to give an indication of population density, soil samples must be taken or the females or cysts must be observed directly on the host roots. Detection based on host plant symptoms and identification by morphological and molecular methods are detailed in EPPO (2009).
Surveys of the numbers and distribution of potato cyst nematode are prerequisites for making informed choices for their management. Samples taken within a field are either to check whether potato cyst nematode is present or not in the field for statutory purposes or to determine the extent of the infestation, which might include a determination as to what species is present.
At one time, it was considered that nematodes had a haphazard distribution in the field but this has been disproved. Aspects of the environment and ecological factors such as disease, predators and soil type favour aggregated distributions. Many models help to describe distributions, for example Taylor's Power Law (Taylor, 1961), Iwao's regression model (Allsopp, 1990) and others. However, geostatistical techniques may provide a more purposeful definition of the spatial distribution of nematodes. Although these techniques are young, 3-D maps can be generated to study nematode population levels more effectively. These methods have already proved useful in mapping other types of field related data (Chellemi et al., 1988) and have recently been applied to the distribution of potato cyst nematodes (Evans et al., 2003).

Symptons


Potato cyst nematodes, in common with other cyst nematodes, do not cause specific symptoms of infestation. Initially, crops will display patches of poor growth and plants in these patches may show chlorosis and wilting. When the tubers are harvested there will be a yield loss and tubers will be smaller. To be confident that these symptoms are caused by potato cyst nematodes and to give an indication of population density, soil samples must be taken or the females or cysts must be observed directly on the host roots. In heavily infested soils, plants have reduced root systems and often grow poorly due to nutrient deficiencies and to water stress. Plants may senesce prematurely as they are more susceptible to infection by fungi such as Verticillium spp. when heavily invaded by potato cyst nematodes.
Direct damage to roots and the yield of tubers
The infective second stage juveniles of both G. rostochiensis and G. pallida respond to environmental conditions when hatching. There is a short period of time for the second stage juvenile to locate a host root and begin the process of invasion, usually just behind the root tip. The juveniles then position themselves next to the stele within the root where, after a few hours, they will establish a feeding site (syncytium), which will become their nutrient source until their death. If a susceptible variety of potato is planted the plants will soon show signs of attack particularly when nematode density is high. In resistant plant varieties juveniles still hatch from the cyst and invade the plant roots, but they are unable successfully to establish a feeding site or syncytium. In this situation, males are more likely to be produced than females, as males have negligible nutrient requirements compared to females. Nevertheless, even resistant crops may show signs of attack.
The reduction in the yield of potato tubers, depending on the cultivar grown, is also related to or dependent on the plant's ability to tolerate the effects of nematode attack. The effects of potato cyst nematode on the plant include water stress and early senescence of the leaves. A heavily infested plant is unlikely to produce 100% ground cover with its reduced canopy of leaves. Many field studies have monitored the progression of ground cover by leaves and correlated the findings with yields (see Trudgill et al., 1998).

Impact

G. rostochiensis is a world wide pest of temperate areas, including both temperate countries and temperate regions of tropical countries, for example India’s Nigrilis region. Distribution is linked to that of the potato crop. Potato cyst nematode is considered to have originated from the Andes region of South America, from where it spread to Europe with potatoes. The ease with which it has been transported across continents proves what a resilient pest it is. The cyst form which adheres to host roots, stolons and tubers and to soil particles during transportation gives rise to new infestations where climate and food source are both available and favourable.

Hosts


The major hosts of G. rostochiensis are restricted to the Solanaceae, in particular potato, tomato and aubergine (Ellenby, 1945, 1954;Mai, 1951, 1952;Winslow, 1954;Stelter, 1957, 1959, 1987;Roberts and Stone, 1981;Sullivan et al., 2007). A number of weeds in the Solanaceae are also hosts.
In addition to the main hosts listed, the following plants are hosts of G. rostochiensis:
Datura tatula, D. ferox, Hyoscyamus niger, Lycopersicon aureum, L. glandulosum, L. hirsutum, L. esculentum peruvianum, L. pimpinellifolium, L. pyriforme, L. racemigerum, Nicotiana acuminata, Physalis longifolia, P. philadelphica, Physochlaina orientalis, Salpiglossis sp., Saracha jaltomata, Solanum acaule, S. aethiopicum, S. ajanhuiri, S. ajuscoense, S. alandiae, S. alatum, S.americanum, S. anomalocalyx, S. antipoviczii, S. armatum, S. ascasabii, S. auriculatum, S. asperum, S. aviculare, S. berthaultii, S. blodgettii, S. boergeri, S. brevidens, S. brevimucronatum, S. bukasovii, S. bulbocastanum, S. calcense, S. calcense × S. cardenasii, S. caldasii, S. canasense, S. capsicibaccatum, S. capsicoides, S. cardiophyllum, S. carolinense, S. chacoense, S. chaucha, S. chenopodioides, S. chloropetalum, S. citrillifolium, S. coeruleiflorum, S. commersonii, S. curtilobum, S. curtipes, S. demissum, S. demissum × S. tuberosum, S. dulcamara, S. durum, S. elaeagnifolium, S. ehrenbergii, S. famatinae, S. fraxinifolium, S. fructo-tecto, S. garciae, S. gibberulosum, S. giganteum, S. gigantophyllum, S. gilo, S. glaucophyllum, S. goniocalyx, S. gourlayi, S. gracile, S. heterophyllum, S. heterodoxum, S. hirtum, S. hispidum, S. indicum, S. integrifolium, S. intrusum, S. jamesii, S. jujuyense, S. juzepczukii, S. kesselbrenneri, S. kurtzianum, S. lanciforme, S. lapazense, S. lechnoviczii, S. leptostygma, S. ligustrinum, S. longipedicellatum, S. luteum, S. macolae, S. macrocarpon, S. maglia, S. malinchense, S. mamilliferum, S. marginatum, S. mauritianum, S. melongena, S. miniatum, S. mochiquense, S. multidissectum, S. muricatum, S. neocardenasii, S. nigrum, S. nitidibaccatum, S. ochroleucum, S. okadae, S. oplocense, S. ottonis, S. pampasense, S. parodii, S. penelli, S. photeinocarpum, S. phureja, S. pinnatum, S. pinnatisectum, S. platense, S. platypterum, S. polyacanthos, S. polyadenium, S. prinophyllum, S. quitoense, S. radicans, S. raphanifolium, S. rostratum, S. rybinii S. salamanii, S. saltense, S. sambucinum, S. sanctae-rosae, S. sarrachoides, S. scabrum, S. schenkii, S. schickii, S. semidemissum, S. simplicifolium, S. sinaicum, S. sisymbrifolium, S. sodomaeum, S. soukupii, S. sparsipilum, S. spegazzinii, S. stenotomum, S. stoloniferum, S. suaveolens, S. subandigenum, S. sucrense, S. tarijense, S.tenuifilamentum, S. tlaxcalense, S. tomentosum, S. toralopanum, S. triflorum, S. tuberosum ssp. andigena, S. tuberosum ssp. tuberosum, S. tuberosum 'Aquila', S. tuberosum 'Xenia N', S. utile, S. vallis-mexicae, S. vernei, S. verrucosum, S. villosum, S. violaceimarmoratum, S. wittmackii, S. wittonense, S. xanti, S. yabari and S. zuccagnianum.
Note Oxalis tuberose (Oca), has been extensively tested in host range tests by Sullivan et al. (2007) and has been declared a non-host on this basis.


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

P. hysterophorus is an erect, much-branched with vigorous growth habit, aromatic, annual (or a short-lived perennial), herbaceous plant with a deep taproot. The species reproduces by seed. In its neotropical range it grows to 30-90 cm in height (Lorenzi, 1982, Kissmann and Groth, 1992), but up to 1.5 m, or even 2.5 m, in exotic situations (Haseler, 1976, Navie et al., 1996). Shortly after germination the young plant forms a basal rosette of pale green, pubescent, strongly dissected, deeply lobed leaves, 8-20 cm in length and 4-8 cm in width. The rosette stage may persist for considerable periods during unfavourable conditions (such as water or cold stress). As the stem elongates, smaller, narrower and less dissected leaves are produced alternately on the pubescent, rigid, angular, longitudinally-grooved stem, which becomes woody with age. Both leaves and stems are covered with short, soft trichomes, of which four types have been recognized and are considered to be of taxonomic importance within the genus (Kohli and Rani, 1994).;Flower heads are both terminal and axillary, pedunculate and slightly hairy, being composed of many florets formed into small white capitula, 3-5 mm in diameter. Each head consists of five fertile ray florets (sometimes six, seven or eight) and about 40 male disc florets. The first capitulum forms in the terminal leaf axil, with subsequent capitula occurring progressively down the stem on lateral branches arising from the axils of the lower leaves. Thousands of inflorescences, forming in branched clusters, may be produced at the apex of the plant during the season. Seeds (achenes) are black, flattened, about 2 mm long, each with two thin, straw-coloured, spathulate appendages (sterile florets) at the apex which act as air sacs and aid dispersal.

Hosts

P. hysterophorus is known to reduce the yield of various crops and to compete with pasture species in various countries. However, the yield loss and specific effects on the crops have not been quantified in all countries (Rubaba et al., 2017).;In Australia, the main impact of P. hysterophorus has been in the pastoral region of Queensland, where it replaces forage plants, thereby reducing the carrying capacity for grazing animals (Haseler, 1976, Chippendale and Panetta, 1994). Serious encroachment and replacement of pasture grasses has also been reported in India (Jayachandra, 1971) and in Ethiopia (Tamado, 2001, Taye, 2002). The weed is also able to invade natural ecosystems, and has caused total habitat changes in native Australian grasslands and open woodlands (McFadyen, 1992).;In India, the yield losses are reported as up to 40% in several crops and a 90% reduction of forage production (Gnanavel, 2013). P. hysterophorus is now being reported from India as a serious problem in cotton, groundnuts, potatoes and sorghum, as well as in more traditional crops such as okra (Abelmoschus esculentus), brinjal (Solanum melongena), chickpea and sesame (Kohli and Rani, 1994), and is also proving to be problematic in a range of orchard crops, including vineyards, olives, cashew, coconut, guava, mango and papaya (Tripathi et al., 1991, Mahadevappa, 1997, Gnanavel, 2013).;Similar infestations of sugarcane and sunflower plantations have recently been noted in Australia (Parsons and Cuthbertson, 1992, Navie et al., 1996), whilst in Brazil and Kenya, the principal crop affected is coffee (Njoroge, 1989, Kissmann and Groth, 1992). In Ethiopia, parthenium weed was observed to grow in maize, sorghum, cotton, finger millet (Eleusine coracana), haricot bean (Phaseolus vulgaris), tef (Eragrostis tef), vegetables (potato, tomato, onion, carrot) and fruit orchards (citrus, mango, papaya and banana) (Taye, 2002). In Pakistan, the weed has been reported from number of crops, including wheat, rice, sugarcane, sorghum, maize, squash, gourd and water melon (Shabbir 2006, Shabbir et al. 2011, Anwar et al. 2012).;In Mexico, the species is reported as a weed in cotton, rice, sugarcane, Citrus spp, beans, safflower, sunflower, lentils, corn, mango, okra, bananas, tomato, grapes, alfalfa, chili peppers, luffa, marigolds and other vegetables and fruit orchards. It is also a weed in nurseries. In Argentina is reported as a weed of tobacco fields (CONABIO, 2018).;Gnanavel (2013) also reports the following detrimental effects of P. hysterophorus on crops: it inhibits nitrogen fixing bacteria in legumes, the vast quantity of pollen it produces (ca. 624 million/plants) inhibits fruit setting, it is an alternative host for viruses that cause diseases in crop plants, and it is an alternative host for mealy bugs.

Biological Control
The use of insect and fungal pathogens and the exploitation of allelopathic plants is considered by Kaur et al. (2014) as the most economical and practical way to manage the infestations of the species. Biological control has been, and continues to be, considered the best long-term or sustainable solution to the parthenium weed problem in Australia (Haseler, 1976, McFadyen, 1992) and because of the vast areas and the socio-economics involved, this approach has also been proposed for India (Singh, 1997). South Africa was the first country in Africa to implement a biological control program against the species in 2003 (Rubaba et al., 2017). Four host-specific biocontrol agents have been released sequentially since 2010 after evaluation of their suitability, with variable establishment and spread (Strathie et al., 2016).;The use of insects as biocontrol agents had been tried in various countries (Kaur et al., 2014). Searches for, and evaluation of, coevolved natural enemies have been conducted in the neotropics since 1977. So far, nine insect species and two fungal pathogens have been introduced into Australia as classical biological control agents (Julien, 1992, McClay et al., 1995, Navie et al., 1996, Dhileepan and McFadyen, 1997, Evans, 1997a). Callander and Dhileepan (2016) report that most of these agents have become established and have proven effective in central Queensland, but that the weed is now spreading further into southern Queensland where the biocontrol agents are not present. Several of the agents are therefore now being redistributed into south and southeast Queensland.;The rust fungus, Puccinia abrupta var. partheniicola, is a prominent natural enemy in the semi-arid uplands of Mexico (Evans, 1987a, b), but since its release in Queensland in 1992, climatic conditions have been largely unfavourable (Evans, 1997a, b). It was accidentally introduced into Kenya (Evans, 1987a) and Ethiopia in mid-altitudes (1400-2500 masl) with disease incidence up to 100% in some locations (Taye et al., 2002a). Screening of another rust species (Puccinia melampodii) from Mexico was carried out (Evans, 1997b, Seier et al., 1997) and released in Australia in the summer of 1999/2000 (PAG, 2000). This fungus was later renamed Puccinia xanthii Schwein. var. parthenii-hysterophorae Seier, H.C.Evans & ç.Romero (Seier et al., 2009). Retief et al. (2013) report on specificity testing carried out in quarantine facilities in South Africa, and conclude that the fungus is suitable for release as a biological control agent of P. hysterophorus in South Africa. The authors suggest that this species has more potential for biocontrol in South Africa than Puccinia abrupta, which may have little impact in the low-altitude, high-temperature areas of the country where the weed is spreading.;In India, the mycoherbicide potential of plurivorous fungal pathogens belonging to the genera Fusarium, Colletotrichum, Curvularia,Myrothecium and Sclerotium, has and is being evaluated (Mishra et al., 1995, Evans, 1997a). Parthenium phyllody disease caused by the phytoplasma of faba bean phyllody group (FBP) was reported to reduce seed production by 85% (Taye et al., 2002b) and is being evaluated for use as a biological control agent in Ethiopia. Kaur and Aggarwal (2017) have tested an Alternaria isolate found on the weed, and report that it is worth investigating as a mycoherbicide for control of parthenium. Metabolites of Alternaria japonica and filtrates of Alternaria macrospora have caused significant damage to Parthenium (Kaur et al., 2015, Javaid et al., 2017).;Among the established insect biocontrol agents, the leaf-feeding beetle, Zygogramma bicolorata, the stem-galling moth, Epiblema strenuana, the stem-boring beetle, Listronotus setosipennis, and the seed-feeding weevil, Smicronyx lutulentus, are proving to be the most successful when climatic factors are favourable (McFadyen, 1992, Dhileepan and McFadyen, 1997, Evans, 1997a). Some control of parthenium weed has also been achieved in India with Z. bicolorata (Jayanth and Visalakshy, 1994, Singh, 1997, Sarkate and Pawar, 2006), although there has been controversy concerning its taxonomy and host specificity (Jayanth et al., 1993, Singh, 1997). Shabbir et al. (2016) reported that Z. bicolorata was most effective when applied in higher densities and at early growth stages of the weed. The distribution of this leaf beetle in South Asia was investigated by Dhileepan and Senaratne (2009), when it was present in many states in India, and in the Punjab region of Pakistan. Shrestha et al. (2011) reported that Z. bicolorata arrived in the Kathmandu Valley of Nepal in August 2010, and that by September it had spread over half of the valley areas where P. hysterophorus was present, although damage to the weed was only appreciable at one site.;Z. bicolorata has been seen attacking sunflowers in India and the use of Epiblema strenuata has not been effective, as it was found affecting Guizotia abyssinica crops (Kaur et al., 2014). More recently, Z. bicolorata and L. setosipennis have been released in South Africa and S. lutulentus is being evaluated under quarantine. Before approval as a biocontrol agent in South Africa in 2013, extensive testing suggested that Z. bicolorata would not become a pest of sunflowers in the country (McConnachie, 2015).;The use of antagonistic, competitor plants, such as Cassia spp. and Tagetes spp., has been recommended to control and replace P. hysterophorus in India (Mahadevappa and Ramaiah, 1988, Evans, 1997a, Mahadevappa, 1997, Singh, 1997). In Australia, Bowen et al. (2007) tested a number of grass and legume species against the growth of parthenium weed plants and identified further species that could suppress weed growth. Recently, Khan et al. (2013) tested a number of native and introduced pasture species and identified several of them to be suppressive against parthenium weed in both glasshouse and field conditions. The sowing of selected pasture plants in infested areas can suppress the growth of parthenium weed by as much as 80% and also provide improved fodder for stock (Adkins et al., 2012). Shabbir et al. (2013) showed that the suppressive plants and biological control agents can act synergistically to significantly reduce both the biomass and seed production of parthenium weed under field conditions. The suppressive plants strategy is easy to apply, sustainable over time, profitable under a wide range of environmental conditions and promotes native plant biodiversity. Species reported as effectively outcompeting P. hysterophorus are Cassia sericea, C. tora, C. auriculata, Croton bonplandianum, Amaranthus spinosus, Tephrosia purpurea, Hyptis suaveolens, Sida spinosa, and Mirabilis jalapa. Extracts of Imperata cylindrica, Desmostachya bipinnata, Otcantium annulatum, Sorghum halepense Dicanthium annulatum, Cenchrus pennisetiformis, Azadirachta indica, Aegle marmelos and Eucalyptus tereticornis are reported as inhibiting the germination and/or growth of P. hysterophorus (Kaur et al., 2014).

Source: cabi.org
Description


Eggs - elliptical or ovoid in shape, milky-white and shiny when first laid, 0.5-0.8 mm long, 0.25-0.35 mm wide (Bergamin, 1943;Hernandez-Paz and Sanchez de Leon, 1978;Johanneson, 1984).

Recognition

H. hampei can be detected in the trees and coffee beans.
Tree - inspect the berries and look for a small cylindrical perforation. Look at the lower branches and fallen berries as these may be more likely to be infested. There are numerous sampling methods, many based on counting all berries on 30 or more branches over a hectare and evaluating percentage attack. As yet there is no easy or universal way to relate level of crop attack to future loss at harvest. A figure of 5% infested berries is often used as an economic threshold for field control activities, but more study on this is needed.
Coffee beans - as the perforation on berries may be difficult to see, rub suspect beans between the hands to remove the parchment and look for the perforation. Often a small indentation will be present where the borer started to attack but failed to establish itself.
A trap based on ethanol and methanol has been developed but it also catches many other scolytids. It is useful to monitor emergence flight activity, most notably when rains follow a dry period. French research has renewed interest in trapping as a form of control, initial results have been are encouraging though more research needs to be done to confirm the economic viability of this method (Dufour et al., 1999). Fernandes et al. (2014) found that mass trapping could reduce attacks, but not below an economic threshold.

Symptons


Attack by H. hampei begins at the apex of the coffee berry from about eight weeks after flowering. A small perforation about 1 mm diameter is often clearly visible though this may become partly obscured by subsequent growth of the berry or by fungi that attack the borer. During active boring by the adult female, she pushes out the debris, which forms a deposit over the hole. This deposit may be brown, grey or green in colour.
Infestation is confirmed by cutting open the berry. If the endosperm is still watery, the female will be found in the mesoderm between the two seeds, waiting for the internal tissues to become more solid. If the endosperm is more developed, the borer will normally be found there amongst the excavations and irregular galleries that it has made. The borer sometimes causes the unripe endosperm to rot, most commonly by species Erwinia, causing it to turn black (Sponagel, 1994) and the borer to abandon the berry.

Impact

H. hampei, otherwise known as the coffee berry borer, is the most serious pest of coffee in many of the major coffee-producing countries in the world. The scolytid beetle feeds on the cotyledons and has been known to attack 100% of berries in a heavy infestation. Crop losses can be very severe and coffee quality from damaged berries is poor. H. hampei has been transported around the world as a contaminant of coffee seed and very few coffee-producing countries are free from the borer. Its presence in Hawaii was confirmed in 2010 and Papua New Guinea and Nepal remain free of the pest: in Papua New Guinea an incursion prevention programme was mounted in 2007 (ACIAR, 2013) to reduce chances of invasion from Papua Province (Indonesia). There is no simple and cheap method of control of H. hamepi.

Hosts

H. hampei is sometimes reported attacking and breeding in plants other than coffee, however there are few convincing published studies of this with supporting expert taxonomic identification. However, a Colombian study (L Ruiz, Cenicafé, Centro Nacional de Investigaciones de Café, Colombia, personal communication, 1994) reports rearing the borer through to adulthood on seeds of Melicocca bijuga and a Guatemalan study (O Campos, Anacafé, Asociacion Nacional del Café, Guatemala, personal communication, 1984) reports the same for Cajanus cajan. Vega et al. (2012) reviewing older little-known literature including that of Schedl (1960), make the case that the African host range may be broader than previously suspected. As there is much current interest in mass production of the borer, further studies of alternative food sources would be of interest. Nevertheless, all field studies of the borer suggest that coffee is the only primary host and that population fluctuations are hence due almost entirely to its interaction with coffee and not to the presence of alternative hosts.

Host plant resistance

Chevalier (cited in Le Pelley, 1968) found Coffea liberica almost immune to H. hampei followed by C. excelsa, C. dewerei, C. canephora and C. arabica in increasing order of attractiveness to the borer. Villagran (1991) found that. H. hampei had difficulty in penetrating the hard exterior of C. liberica berries. However, Roepke (in Le Pelley, 1968) states that C. liberica is preferentially attacked. Extensive studies by Kock (1973) reported C. canephora variety Kouilou (or Quoillou) is attacked less than the Robusta variety.
Villagran (1991) found C. kapakata supporting very significantly fewer immature stages of the borer than other varieties and some tendency for C. arabica variety Mundo Novo also to support fewer progeny. Olfactometry tests by Duarte (1992) showed C. kapakata to be significantly less attractive. C. kapakata appears to be one of the most resistant coffee species currently known but this is not a commercial variety and neither the berries nor the plant resemble a coffee plant to the casual observer.
Romero and Cortina-Guererro (2004) in laboratory studies in Colombia found no difference in levels of antixenosis (deterrence to attack coffee in field tests) of various coffee varieties (including C. arabica Caturra, various Ethiopian accessions as well as C. liberica). However Romero and Cortina-Guererro (2007) did find differences in antibiosis (expressed as fecundity) with Ethiopian accession CC532 and C. liberica both yielding significantly fewer borer progeny.
Gongora et al. (2012) confirmed the inhibitory effects of C. liberica through a functional genomics study using ESTs libraries, cDNA microarrays and an oligoarray containing 43,800 coffee sequences. The results allowed for a comparison of C. liberica vs. C. arabica berry responses to H. hampei infestation after 48 h. Out of a set of 2500 plant sequences that exhibited differential expression under H. hampei attack, twice the number were induced in C. liberica, than in C. arabica. One of the identified biochemical pathways was the one that leads to the production of isoprene. The authors studied the effect of isoprene on H. hampei by monitoring the development of the insect from egg to adult, using coffee-artificial diets amended with increasing concentrations of isoprene. Concentrations of isoprene above 25 ppm caused mortality and developmental delay in all insect stages from larva to adult, as well as the inhibition of larvae moulting.
Hence it seems certain that varying amounts of resistance or antibiosis to the borer exists within species of Coffea. Such resistance to attack or even moderate antibiosis is worthy of further study because an increase in development time and/or decrease in fecundity could have a pronounced effect on infestation levels. Conventional breeding to introduce such inhibition from outside the Arabica genome might be difficult however, hence genetic engineering may be increasingly considered in the future.
A team of CIRAD scientists were the first to succeed in producing a transgenic coffee plant with Bt resistance to leafminers but there is no information about its effect on H. hampei (Leroy et al., 2000). Scientists from Brazil and Colombia (Barbosa et al., 2010) transformed C. arabica by introducing an enzyme inhibitor from the common bean (Phaseolus vulgaris). Beans have evolved an amylase enzyme inhibitor (or ‘starch blocker’) to make them less palatable to attacking insects. They demonstrated that crude seed extracts from genetically transformed C. arabica plants expressing the α-amylase inhibitor-1 gene (α-AI1) under the control of the common bean P. vulgaris seed-specific promoter PHA-L, inhibited 88 % of H. hampei α-amylases during in vitro assays. Since then, offspring from these GM coffee plants have been cultivated under greenhouse conditions to study the heredity, stability and expression of the α-AI1 gene. Subsequently Albuquerque et al. (2015) carried out in vivo assays of H. hampei development in berries of the transformed plants. A 26-day assay showed that the lifecycle of H. hampei was still completed, though significantly fewer offspring developed than on non-transformed control beans. Other tests showed that gene expression occurred only in the endosperm tissue. Commercial interest in developing transgenic coffee resistant to pests and diseases is still low however and might meet considerable consumer resistance.

Monitoring

Theoretically it would be possible to develop a forecasting model to predict upsurges of H. hampei, because under some conditions, especially after a long dry spell with high temperatures, large populations develop on fallen berries which then emerge after early rains. This however would require regular field monitoring and dissections of sampled berries and the costs of mounting such an exercise are probably too high. However, even occasional and non-intensive monitoring of borer during the post-harvest dry season, could give field technicians a feel for the build-up of populations that could be translated into warnings to farmers in exceptional circumstances. Recent El Niño events which cause prolonged hot and dry conditions, almost invariably give rise to an upsurge in infestations.
Traps with a 1:1 ethanol + methanol lure can be used to trap flying borer. Numbers caught relate quite closely to nearby total populations (Mathieu et al., 1999) so could be used to monitor borer populations. However, the traps placed outside an infested plot catch very few insects, so the power of the trap is low. This means that its use to detect borer flying into a quarantined zone is questionable. For that purpose simply checking coffee trees for infestations is probably quicker, more sensitive and cheaper. This is probably also true for routine monitoring of borer populations. Traps are now used sometimes as part of an IPM control strategy, i.e. for control rather than monitoring (Dufour and Frérot, 2008). Spectacular catches have been achieved in El Salvador (Dufour et al., 2004) and were related to measured declines in infestation. However results can be very variable. Fernandes et al. (2014) deployed 900 traps in four coffee farms and achieved a 57% reduction infestation, but levels were still above an economic loss threshold. It seems likely that traps can be effective in specific conditions, when placed after early rains when borers are emerging and when there are few berries to compete for the traps’ attractiveness. However the proportion of borers trapped to total infestation levels is always low 5%) so it is questionable whether traps are cost effective, especially since they need regular servicing to replenish the lure, clear debris etc., something that most farmers are not good at. Hence the traps need to be evaluated for specific coffee-growing conditions and results weighed against costs of the traps, their regular servicing and farmers’ willingness to service them regularly.

Biological Control
The two bethylid parasitoids, Cephalonomia stephanoderis and Prorops nasuta have been introduced from Africa to India and many Latin-American countries in the 1980s and 1990s. The few studies undertaken on their effectiveness suggest that in general they have only a moderate controlling effect and that it is rare to find more than 5% of perforated berries parasitized one or more years after releases were made (Barrera, 1994). However a follow-up study seven years after a campaign to rear and release large numbers of C. stephanoderis in different coffee growing areas of Pulney Hills, Tamil Nadu, India, recorded 16-45% parasitism from five different areas (Roobakkumar et al., 2014). Generally low parasitism may be because the berries are harvested before the wasps have a chance to emerge, though more studies are needed to explain their scarcity in the field. Both species parasitize only one berry: the female enters and stays with her brood, rather similar to the borer's maternal behaviour. From the point of view of biocontrol this is unfortunate as a parasitoid that lays eggs in many berries might be more effective. Mass release studies of C. stephanoderis in Colombia and other countries have been carried out but the costs of mass production are uneconomical and likely to remain so because of the high cost of the diet (coffee beans) for the borer host.<br>Phymastichus coffea was seen as a promising biocontrol agent because it attacks adults and thus might help to prevent establishment of the borer in the endosperm, where economic damage is caused. It can also parasitise borers from more than one berry and the few studies on this in the field have suggested that it may be more effective control agent than the bethylids (Baker, 1999). However, to date there are no follow up field studies that suggest it is having any suppressive effect on the borer in the field.<br>The fungus Beauveria bassiana is found naturally wherever H. hampei is present. In humid climates infection may reach more than 50% and is probably the most significant natural control agent of H. hampei. Pascalet (1939) found it prevalent in the forest zone of Cameroon and concluded that conditions favourable to an outbreak were a dense borer population, 20-30°C temperature, sufficient rain to produce the humidity necessary for vigorous sporulation, followed by one or two sunny days to induce an even distribution of spores, followed by light rains to favour development of spores on the bodies of the borers. Intensive efforts in Colombia, Nicaragua, Mexico and Ecuador have been made to develop an effective mycopesticide based on B. bassiana. Results have been very variable with sprays (with varying concentrations of fungal spores/tree) causing anything from 10-86% mortality (Lacayo, 1993;Sponagel, 1994;Bravo, 1995;Bustillo and Posada, 1996;Baker, 1999). High field mortality of H. hampei in the entry canal of the berry (80%+) have been achieved but only at uneconomically high doses. At lower doses the mortality is usually between 20-50% of adult females entering the berry. Further problems relate to the viability and virulence of commercially prepared formulations of the fungus and the product requires careful quality control and monitoring to ensure acceptable standards. Currently in Colombia, despite a concerted research and extension effort over many years, few farmers still apply the fungus. Benavides et al. (2012) suggest that applying a mix of B. bassiana strains may improve virulence. Another approach has been to inject B. bassiana into coffee in the hope that it might establish inside the plant and act as an endophyte to attack the borer when it drills into the berry (Vega et al., 2005).<br>More recently efforts to increase the virulence of Metarhizium anisopliae (a fungus which occasionally attacks H. hampei), by inserting a scorpion toxin gene through genetic engineering (Pava-Ripoll et al., 2008).<br>Vega et al. (2002a) have also studied the presence of Wollbachia in H. hampei, a bacterial infection that may be the cause of its skewed sex ratio. However to date there seems to be no practical way to use this knowledge to devise a novel control method.<br>In general nematodes would be difficult to apply to coffee trees, but might be easier to apply to the ground under the trees where the microclimate might be very suitable for them. The fallen berries under the tree are known to be a very important reservoir of re-infestation and yet difficult to control either by chemicals, fungi or manual collection and experimental releases of parasitoids suggest that few of them attack fallen berries. Hence what is needed is something that could actively search for an infested berry and tunnel its way into the berry to attack the coffee berry borer inside. Lopez-Nuñez of Cenicafé, Colombia, working with Steinernema carpocapsae (All strain), S. glaseri and Heterorhabditis bacteriophora has achieved infection and mortality of H. hampei in laboratory and small-scale field trials (Baker, 1999). Efforts continue to evaluate its performance in larger field trials.<br>In recent years there have been a number of studies to evaluate the effect of bird predation (e.g. Johnson et al., 2010;Karp et al., 2013) which through exclusion cage experiments show significant control effects in heavily infested field conditions. The presence of H. hampei in the diet of some birds has been confirmed through DNA analysis of faecal samples (Karp et al., 2014), however less than 10% of birds tested positive for H. hampei. Exclusion studies have also been carried out with ants (e.g. Solenopsis geminata;Trible and Carroll, 2014) which show a significant predation effect. To date though, no long term field experiments have been performed which demonstrate reliable and significant predation from a range of naturally occurring predators. The main difficulty is that generalist predators tend to search for high density prey and may switch away from H. hampei at levels above an acceptable economic threshold.<br>Thus despite intensive efforts over the last 25 + years, the impact of biocontrol on H. hampei continues to be disappointingly low.
Integrated Pest Management
A crude version of IPM is employed by many farmers, involving some cultural control and insecticidal spraying. Different schemes, based on sampling and economic thresholds have been developed (Decazy and Castro, 1990), but it is difficult to establish simple thresholds on a perennial crop with a prolonged flowering period and a long berry development period. Further, if a chemical control option is selected, it needs to be carried out many weeks (16 or more) before harvest when the borers are in their most susceptible stage (Decazy et al., 1989;Barrera, 1994). Establishment of an economic threshold is equally difficult when the coffee farmer is unsure of the impact of the post-harvest borer population on the next harvest many months hence. Extensive studies of Colombian farmers attest to the difficulty of adoption of complex IPM regimes (Duque and Chaves, 2000). In many cases a value of 5% berries damaged is used as a ‘rule-of-thumb’ action threshold.<br>The main issue is that there is no simple and cheap method to control this insect. This has led to the promotion of a very wide range of combinations of control elements which has sometimes resulted in quite complex IPM schedules that farmers, especially smallholders, find difficult to adopt. It is frequently not clear that each added element exerts a significant or cost-effective increment to control. To an extent this is due to the complex nature of the pest, which is cryptic and may have multiple overlapping populations growing on several populations of berries resulting from different flowerings. This situation demands extensive and multi-year research studies which are frequently beyond the budgets of small research facilities of most coffee countries. The prospects for IPM of H. hampei are dealt with in detail in Baker (1999).

Source: cabi.org
Description


Annual herb to subshrub, many branched, erect to sprawling, 10-60 cm tall. Stem viscid-pilose, with intermixed glandular and non-glandular hairs. Leaves opposite, subsessile to short petiolate, elliptic, oval ovate, rarely obovate, with acute apex, 1.5-6 cm long. Flowers arising from leaf axils, solitary, 4.5-7 mm long, floral tube sparsely pubescent with glandular hairs, green, calyx lobes unequal, deltoid, short bristle-tipped, 6 petals, 2-3 mm long, linear-elliptic, pale purple, stamens longer than the floral tube. 3 seeds, 2 mm long, lenticular, olive to brown with pale edges (Graham, 1975).

Impact

Cuphea carthagenensis is an annual herb of moist habitats. Although its native range is uncertain, it is likely to cover parts of Central America and the Caribbean, and South America. It has become naturalized widely outside of its native range, in Central America, North America, the Caribbean, Oceania, and Asia. In its native and introduced range it is a weed of cultivated lands and disturbed sites, and sometimes invades intact natural areas in low densities. In Indonesia, where it dominates maize (Zea Mays), it is considered one of the top ten weeds (Solfiyeni et al., 2013). Several other species of Cuphea are also recorded as invasive (e.g. PIER, 2015).

Hosts

C. carthagenensis has been listed as a weed of a number of agricultural crops. In its native range in Brazil it is considered one of the most important weeds by (Pio, 1980) because of its abundance and competitive effects in Brazilian state of São Paulo, but which crops were affected were not specified. In Hawaii, USA, C. carthagenensis is a weed of cucumber (Cucumis sativus) (Valenzuela et al., 1994). In Assam, India, it is a dominant weed of rice (Oryza sativa) (Randhawa et al., 2006). In Indonesia, it dominates corn (Zea Mays) plantings (Solfiyeni et al., 2013). On Vanuatu, it is a serious pest of coconut (Cocos nucifera) groves and in pastures (Mullen, 2009). It is also a weed of taro (Colocasia esculenta) in Fiji (Heap, 2015) and of pastures (Robert, 1970). Laca-Buendia et al. (1989) reported it to be a sporadic weed of common bean (Phaseolus vulgaris) in Brazil.


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

T. areolata is an heteroecious rust, producing the aecial stage on spruce cones (Picea spp.) and the uredinial and telial stage on the leaves of wild cherry trees (Prunus spp.).

Recognition

The insides of cone scales should be examined for the tough rounded red-brown aecia, particularly on cones that are open early or that are open in wet weather (Murray, 1955). Leaves of cherry [ Prunus spp.] trees will show dark-purple angular spots on both surfaces;the hemispherical orange-yellow uredinia occur on the lower leaf surface. Telia have been reported to occur only on Prunus padus and Prunus virginiana (Hylander et al., 1953) and microscopic examination of the epidermis is required to see the densely packed septate teliospores.

Symptons

Whitish spermogonia on the outside of infected cone scales generate a sugary liquid with a strong odour (Murray, 1955;Wilson and Henderson, 1966). The large hemispherical or rounded aecia on the inner surface of scales cause the cones to open early and/or remain open in wet weather (Murray, 1955). Quantities of yellow aeciospores are shed. The resulting infection of Prunus leaves causes angular, violet or reddish-brown spots on the upper leaf surface, with yellow uredinial pustules shedding urediniospores on the lower surface. Telia are in the leaf epidermis, eventually causing reddish-brown to dark-brown discolouration in the spots on the upper surface. Necrosis of leaf tissue may result in a “shot hole” effect, when the affected tissue falls out (Smith et al., 1988).
Roll-Hansen (1965) found infection of young spruce trees to cause crooked stems and necrotic stem lesions with a slightly swollen bark area, often accompanied by dieback of the shoot terminus. Hietala et al. (2008) also reported crooked growth that often accompanied dark-brown necrotic lesions in the bark of seedlings and the leader shoots of saplings. Aecia did not appear on the seedling shoots, but could occur on saplings (Hietala et al., 2008).

Impact

T. areolata is a heteroecious rust fungus;an obligate parasite with stages of its life cycle on cones of Picea species and leaves of Prunus spp. Reported from Europe and Asia, the fungus is a Regulated Pest for the USA. It is absent from North America, where susceptible species are native or introduced, and Australia and New Zealand, where such species are introduced. Although usually not a major problem in its native range, this rust could be more damaging as an invasive in other temperate areas. Due to the fact that small amounts of infection may be overlooked, accidental introduction could occur through importation of infected cones carrying aeciospores. The one known introduction to North America involved a tree of Prunus sp. in a garden, from which there was no documented spread.

Hosts

The major aecial host is Picea abies, but Roll-Hansen (1965) found that shoots of the North American Picea engelmannii, introduced in Norway, were also infected;there was no report of the infection of cones. Most other Picea species reported are Asian (Hiratsuka et al., 1992;Chen, 2002). Although there are reports of the rust on the important cultivated fruit trees Prunus cerasus (cherry) and Prunus domestica (plum) (Kuprevich and Transchel, 1957;Gjaerum, 1974), the wild Prunus padus and introduced Prunus serotina and Prunus virginiana are more frequently the telial hosts in Europe (Smith et al., 1988).


Source: cabi.org
Effects Tilletia indica
Description


Teliospores are dark reddish to coppery, dull brown or dark brown, some spores typically black/opaque, globose to subglobose, occasionally with a mycelial fragment (apiculus) attached;24-47 µm diameter (about twice that of Tilletia caries);exospore with thick, truncate, compact projections, 1.5-5 µm high, seen in median view. The opacity of the teliospores (Duran and Fischer, 1961) is one factor that differentiates T. indica from T. walkeri that is found on ryegrass (Lolium spp.) (Castlebury and Carris, 1999);other factors include surface ornamentation and size parameters. Sterile cells are intermingled with teliospores in the sori;very variable, globose, subglobose, frequently lacrymiform, yellowish-brown, 10-28 µm wide at their widest point to 48 µm in overall length, with a well developed stalk;walls laminated, up to 7 µm thick.
Primary sporidia usually 64-79 x 1.5-2 µm;secondary sporidia usually 12-13 x 2 µm.
For more information, see Duran and Fischer (1961), Khanna et al. (1968) and Waller and Mordue (1983).

Recognition


A quarantine procedure for testing seeds of Triticum spp. for T. indica has been described by EPPO (OEPP/ EPPO, 1991b). An EU recommended diagnostic protocol for the detection and identification of T. indica has also been produced (Inman et al., 2003;EPPO, 2007). This protocol has been enhanced for increased sensitivity and specificity by the adoption of more advanced technology (Tan et al., 2010). An updated draft is available from the IPPC website (www.ippc.int).
Crops for seed should be inspected during the growing season, though not while the crop is still green. Field inspection at maturity prior to harvest could be useful, although field symptoms are often very slight and the disease can be difficult to discern even at maturity. Any bunted seeds detected during field inspections should be examined under the microscope for the characteristic teliospores of T. indica. For quarantine purposes, seed should be tested for the presence of the fungus by the washing test (see Seedborne Aspects).
Direct visual observation for Karnal bunt (dry seed inspection) is regarded as insufficient for quarantine purposes because low levels of infection might pass undetected (Agrawal et al., 1986) and even minimal seed infections can substantially contaminate healthy seed lots (Aujla et al., 1988).
Being a non-systemic pathogen, it generally produces not more than four or five bunted kernels in each spike. Detection in the field is very unlikely and the first year of an outbreak usually goes undetected. For instance, detection of T. indica in a seed test sample in Arizona, USA, in 1996 was traced to wheat harvested in 1993 suggesting the pathogen had been present since 1992 (Rust et al., 2005). It had taken at least 4 years for the pathogen to be detected.

Symptons


Symptoms depend on climate and are manifested most clearly when cool/warm humid conditions prevail at heading. The fungus causes a reduction in the length of ears as well as in the number of spikelets of bunted ears. Infected plants may be dwarfed. In general, T. indica rarely infects more than a few spikelets per ear and then the affected grains are not swollen. Oblong or ovoid sori, 1-3 mm diameter, develop, containing dusty, brown to black spore masses. These characteristically smell of decaying fish (trimethylamine) as do those of T. tritici, T. foetida and T. contraversa (EPPO/ CABI, 1996). Feeding studies have revealed no adverse health effects, but consumers can begin to taste and smell the fishiness when 3% or more of grain is affected.
The grain is partially destroyed, the attack starting at the hilum and running along the suture, leaving the endosperm intact and covered by the whole or partly ruptured seed coat. In the case of mild infection, only a black point just below the embryo towards the suture is apparent. In advanced attack, tissues along the suture and adjacent endosperm are replaced by spores. The glumes spread apart, exposing the infected grains, and both glumes and grains may fall to the ground.
For more information, see Holton (1949) and Duran and Fischer (1961).

Impact

T. indica is the fungal pathogen causing Karnal bunt of wheat seeds. Its distribution is mainly limited to northwest India and adjoining countries, North America and South Africa;it is listed as a quarantine pest in Europe, Australia, South America and elsewhere. In North America it was confined to an area in northwest Mexico until 1996, when it was reported from Arizona. Since then, surveys have detected it in a few locations in southwest USA. It has also recently been found in germplasm imported into other continents.

Hosts


The main host of T. indica is wheat (Triticum spp.) (Aujla et al., 1986, 1987);durum wheat and triticale are less susceptible. Plants are infected within 2-3 weeks of heading.
In inoculation experiments Aegilops spp., Bromus spp., Lolium spp. and Oryzopsis showed varying degrees of susceptibility (Royer and Rytter, 1988).


Source: cabi.org
Description

S. glastifolius is an erect perennial herb, often with woody lower stems. Typically it grows to a height of about 1 m (Webb et al., 1988), but plants in sheltered conditions frequently grow to over 2 m tall. However, the majority of plants in the Manawatū region of New Zealand are 1.2 m tall, and it rarely reaches 2 m in Australia. Williams et al. (1999) report stems of 8 cm in diameter, but stems which are 9 cm in diameter at the narrowest point have been measured, with the base up to 11 cm diameter (G Rapson, Massey University, Palmerston North, unpublished data).

Recognition

S. glastifolius is extremely easy to detect during the flowering season, but is rather cryptic at other times, at least in New Zealand. Searching for new infestations or remnants is best done during the flowering period (early spring).

Impact

Senecio glastifolius is an erect perennial herb, native to the Eastern and Western Capes of South Africa. It is sold commercially as an ornamental and is often planted in gardens. It is known to have been introduced to Madeira, the UK and California in the USA and is recorded as invasive in Australia and New Zealand. It grows in shrubland and rocky, damp areas such as riverbanks. Where it is invasive, it grows in disturbed areas, agricultural land, open woodlands and coastal areas. In suitable habitats it is an extremely aggressive weed, producing large numbers of wind dispersed seed, and spreading rapidly, forming dense stands and potentially outcompeting native biodiversity. Ecological niche modelling revealed that, if introduced, this species could become invasive across large areas of the world including the west coasts of Canada, USA and South America and parts of Europe and Africa. Early detection and removal of seedlings, often garden escapes, is likely to be the most effective method of control. In New Zealand, infestations are largely controlled by hand-pulling of plants;however some commercially available herbicides have proved effective. The sale of this species has been banned in Tasmania, Australia and the Taranaki region of New Zealand.

Hosts

There are no known effects of this species on crops in New Zealand, as the plant is restricted to wasteland and coastal areas. It does occur among scrub in extensively grazed farmland, where it may eventually come to restrict productivity of preferred forage plants.

Biological Control
There are no known biological control agents for S. glastifolius (Froude, 2002). However, studies carried out by Brierley (1953) on the host range of chrysanthemum stunt virus found 39 plant varieties, including S. glastifolius, which were susceptible and developed recognizable symptoms.

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

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
Description


Webb et al., (1988) describes V. litoralis as a

Impact

Verbena litoralis is a short-lived herbaceous plant, native to many of the tropical areas of Central and South America. Although the species has spread to other countries from its native environment, and is sometimes regarded as an invasive threat (in Australia and some states of the USA), it often seems to be restricted to disturbed habitats like roadsides, stream banks, tracks and waste places. Information on its effects on other plant species is not well reported, nor is there any evidence to suggest it has any serious impacts on specific environments or ecosystems.

Hosts


No mention found of any particular species affected by its presence.


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

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.
I. clypealis has the head, pronotum and scutellum yellowish, with two black spots on the anterior margin of the vertex in the female, but these spots are absent in the male. The frons is immaculate;there are two black spots on the fronto-clypeus mesad and basad of the ocelli;the clypellus is completely black. The scutellum is yellowish with a a triangular black spot near each basal angle. The forewings are pale ochraceous. Male genitalia are with an aedeagus with two pairs of long appendages. Males are between 3.7 and 4.2 mm in length;females are 3.8-4.2 mm.

Recognition

Detailed examination of the flower panicles is needed to determine the population size for damage assessment and control studies. Verghese et al. (1985) developed a sequential sampling plan for classifying infestation of I. clypealis into light, moderate and severe on the basis of sample counts. Negative binomial distributions for nymphs and adults were fitted. Operating characteristic values, giving the probability of reaching a correct decision for a range of population means for both adults and nymphs, together with average sample number values, were used to predict the average number of trees to be sampled under different sequential plans. In the case of the closely related I. niveosparsus, studies by Tandon et al. (1989) on the spatial distribution of nymphs on mango trees in Karnataka, India, to determine a sampling plan for the pest showed that nymphs were aggregated on the mango panicles. Their distribution was best explained by Iwao's patchiness regression which showed that mean colony size was fixed and that colonies followed a negative binomial series. The optimum sample size recommended was 59 panicles per tree for damage assessment and control studies, and 98 panicles per tree for ecological studies when greater precision was required. Tandon et al. (1989) found no significant differences in the distribution of nymphs between the north, south, east or west portions of the tree or between the upper and lower canopies, indicating that sampling can be conducted from any point on the tree.

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

According to Sohi and Sohi (1990) there are no plants other than mangoes on which I. clypealis will breed;however Viraktamath (1989) and Gnaneswaran et al. (2007) list a range of trees on which adults have been found.

Biological Control
To date there have been few studies where biological control has been attempted against mango leafhoppers, despite the existence of parasitoids and predators (see Natural Enemies). Several fungal pathogens may prove useful for biological control as mentioned by Kumar et al. (1983).<br>Host-Plant Resistance<br>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.

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
Effects Brown spot, Yellows
Description

Leafhoppers of the subfamily Idiocerinae are characterized by a broad, rounded head, extending little between the eyes, and a general 'wedge' shape. Unfortunately, there is no comprehensive taxonomic treatment available to separate all the mango-associated species.;I. nitidulus has been illustrated by Maldonado Capriles (1964) and Hongsaprug (1993). The vertex has brownish suffusions on each side of a central line, the posterior margin and laterally before the eyes are yellowish. The face is with two discal brown spots. The ocellus is inside a round, yellow spot, another spot of the same size and colour is adjacent to this spot. The pronotum is dull pale green with irregular, brownish and yellowish spots and markings. The scutellum is pale ochraceous with three basal blackish or dark-brown spots. The forewing is bronzed and subhyaline, veins are brownish, and the costal area is straw coloured. There are white markings on the forewing near the humeral angle, at the claval cells and on the veins.

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 the bugs excreta (honeydew) on which sooty mould develops, affecting photosynthesis. Some damage may also occur through egg laying into the leaves and flower stems.

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. nitidulus on floral branches was positively associated with the nitrogen content of the branches.

Biological Control
To date there have been few studies where biological control has been attempted against mango leafhoppers, despite the existence of parasitoids (see Natural Enemies).

Source: cabi.org
Description

B. pertusa is a stoloniferous perennial. Stolons often pink, rooting at the nodes, creeping extensively to form a sward. Nodes bearded. Stems geniculately erect 60-100 cm high. Leaves up 10-30 cm long, 2-5 mm wide, apex acute, mainly crowded at the base of the culms, usually glabrous, but with some scattered hairs. Ligule cilate 1-2 mm long. Inflorescence sub-digitate with up to 12 shortly pedunculate purplish racemes each up to 7 cm long, the lowest longer than the central axis, pilose. Sessile spikelet narrowly elliptic 3-4 mm log, lower glume cartilaginous, hairy on the lower half, with one or two pits in upper half;fertile lemma reduced to a slender geniculate awn up to 20 mm (normally 10-17 mm) long. Pedicelled spikelet on densely hairy pedicel up to 3 mm long, glabrous, occasionally pitted, usually sterile. Caryopsis 1.5 to 2 mm long, and shed firmly enclosed in the fertile lemma with sterile lemma and awn still attached.

Impact

B. pertusa is a perennial grass native to eastern and southern Asia. It has been widely introduced outside Asia, in the Americas, Australia and the Pacific, either accidentally or probably in some cases deliberately for use as a forage grass. It has established itself in many habitats where it is able to out-compete native species due to its ability to establish dense mats and shade out slower establishing species. In Australia it is now an established invasive species in both the Northern Territory and central Queensland. It is similarly regarded as invasive in Mexico, in Cuba, Puerto Rico, the Dominican Republic, Anguilla and the Cayman Islands in the Caribbean, in Mauritius, and in New Caledonia, the Marquesas Islands, Midway Atoll and Hawaii in the Pacific. In Hawaii, it is among species threatening the endangered plants Spermolepis hawaiiensis and Wilkesia hobdyi. Through its effects on native vegetation, it likewise threatens the endangered lizard Ameiva polops in the US Virgin Islands, and affects populations of ants and birds in Australia.

Hosts

B. pertusa is rarely recorded as a weed of crops but may impact wild species as noted under ‘Impact on Biodiversity’.

Biological Control
<br>There is no record of any attempt at biological control.

Source: cabi.org
Description


A general description suitable for quarantine purposes is given by Harris et al. (2005), and is summarized here.

Recognition


One of the best methods for detecting invasive ants including T. melanocephalum is via baits. They appear to especially like sugary food. Clark et al. (1982) found that T. melanocephalum was frequently the only ant present on sugar water baits, but also the species most often replaced, suggesting a rapid utilization foraging strategy. Foragers locate and recruit to food quickly (Clark et al., 1982;Lee, 2002). However, they are also often displaced when dominant ants discover food resources (Clark et al., 1982), so observations may need to be made of species dynamics at baits.
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.

Symptons


In crops T. melanocephalum is considered a secondary pest: rather than being a pest itself, it can tend or farm mealybug, scale or aphid populations, protecting these pests from their natural enemies (Fowler et al., 1990;Appel et al., 2004). This protection can result in large herbivore populations. The specific effects and symptoms on each crop are dependent on the specific mealybug, scale or aphid species being tended.

Impact

T. melanocephalum is a small ant species around 1.5 mm in length originating from the Old World tropics. It is considered an invasive and “tramp” ant species: widely associated with humans, it has been moved around the subtropical and tropical world by human activity. This ant is also recorded in heated buildings in areas such as Canada and Finland. It is primarily a household pest, nesting in housing and consuming household food. In areas such as Florida it is considered one of the most important house-infesting pests. However it has been known to affect agricultural production in situations such as greenhouses, especially if it tends honeydew-producing insects and protects these pests from biological control organisms. T. melanocephalum is thought to be capable of transporting pathogenic microbes and is often abundant in hospitals. Some people can suffer a slight, red irritation of the skin following contact with this ant. This ant is listed on the ISSG global invasive species database.

Hosts


It is important to note that no reports were found of T. melanocephalum being considered a significant pest of agriculture or horticulture. In crops it is considered a secondary pest: rather than being a pest itself, it can tend or farm mealybug, scale or aphid populations, protecting these pests from their natural enemies (Fowler et al., 1990;Appel et al., 2004). This protection can result in large herbivore populations. Unlike other invasive ants, however, the results of such tending behaviour in terms of economic damage have not been quantified. T. melanocephalum is also known to consume sugary foods in storage and nectar from plants.


Source: cabi.org
From Wikipedia:

Effect may refer to:

  • A result or change of something
    • List of effects
    • Cause and effect, an idiom describing causality