B. caryophylli is a straight or slightly curved rod with rounded ends, occurring singly or in pairs;it is aerobic, non-sporing, motile with one or several polar flagella, Gram-negative, sudanophilic, 0.35-0.95 x 1.05-3.18 µm.
In PDA culture, colonies are round, smooth and shining with regular margins: while cream-coloured at first, colonies darken with age. On nutrient agar, growth is slow and cells die rapidly;subculturing is not possible after about a week.
B. caryophylli is a straight or slightly curved rod with rounded ends, occurring singly or in pairs;it is aerobic, non-sporing, motile with one or several polar flagella, Gram-negative, sudanophilic, 0.35-0.95 x 1.05-3.18 µm.
To make a reliable diagnosis, many old and young stems should be examined and isolations made from diseased tissue. Microscopic observation of stem sections shows neoformations around infected vessels, plugging of vessels, hyperlignification of their walls and necrosis. Since latent infections on cuttings cannot be readily detected, cuttings should be kept at a relatively high temperature to ensure maximum symptom expression. The bacterium can be reliably detected by immunofluorescence staining (IFAS) and direct isolation even in material with latent infection (Muratore et al., 1986). B. caryophylli has also been detected from inoculated carnation by PCR and LAMP (Loop-mediated isothermal amplification) (Kazushi et al., 2005).
Symptoms may take 2-3 years to manifest themselves, particularly when cuttings are mildly infected and maintained at relatively low temperatures. Foliage becomes greyish-green, later yellowing and wilting and then death may occur.
In stems, at soil temperatures below about 17°C, a rapid multiplication of cells leads to tension around the vessels and longitudinal, internodal stem cracks appear, usually at the base of the plant, and later develop into deep cankers. Initially, this cracking is very similar to the physiological cracking observed in certain cultivars. However, in pathogen-induced cracks, a brownish-yellow bacterial slime is visible, often overgrown with saprophytic fungi such as Mycosphaerella tassiana. In some cases, the extrusions from the cankers leave the stems hollow. At 20-25°C, cankers are more rare and wilting is the common symptom. Visual observation of peeled stems reveals sticky, brownish-yellow, narrow or broad, longitudinal stripes in the vascular tissue;in cross section, these appear as irregular brownish spots with a water-soaked margin.
Roots of infected plants, once wilting occurs, are more or less rotten, the plants being easily pulled out of the soil and, on cutting, roots show discontinuous brown spots which distinguish the disease from that caused by Phialophora cinerescens which leaves the roots apparently symptomless (EPPO/ CABI, 1996a).
Plants may survive about 1-2 months, but secondary invasion by fungi, such as Fusarium spp., accelerates death. Heavily infected cuttings wilt and die before roots are formed. For more information, see Dimock (1950), Hellmers (1958), Lemattre et al. (1964), Garibaldi (1967), Lemattre (1969) and Saddler (1994).
Carnations are the main host. However, Dianthus barbatus and D. allwoodii can be infected through artificial inoculation. In Florida, USA, and Japan, Limonium sinuatum is also reported to be infected (Jones and Engelhard, 1984;Nishiyama et al., 1988).
Shell: dextrally coiled. Juveniles globose. During post-hatching ontogeny shell growth is of planispiral coiling, producing 3.5 to 4 flat whorls in which the juvenile spire is not elevated above the adult whorls and the umbilicus is very widely open. Shell in adults 18-22 mm in height, 48-56 mm in diameter, more-or-less glossy but with growth lines (transverse striate) that are most prominent near the aperture. Aperture plane makes a slight angle with the shell axis (10¡), peristome (aperture margin) generally continuous, but interrupted by prominent callus on parietal wall in immature snails, peristome simple, sharp, but late in ontogeny becoming reflected and thickened. Yellow to brownish ground colour with 3-6 dark red-brown to black spiral bands over periphery and umbilicus, banding pattern can be absent. Adult mass about 500-650 mg. With a weak sexual dimorphism, shell of males tending smaller, thicker and with more rounded aperture. The planispiral shell is orientated vertically.
M. cornuarietis feeds on subsurface vegetation, typically severing stems and consuming these cuttings.
C. juncea is a thin, spindly, herbaceous perennial. In addition to a deep (2 m) taproot, it has lateral roots that produce daughter rosettes. Plants also grow from buds on root fragments cut by cultivation or other equipment. It has a basal rosette of dandelion-like leaves, up to 20 cm long, glabrous. They are rush-like in appearance, up to 150 cm bright green or yellow-green with multiple, slender, leafless branches and reddish downward-pointing hairs near the base. Rosette and stem leaves are deciduous. Flowers 1-2 cm across have yellow, daisy-like capitulae, borne singly or in small clusters, almost sessile on the virtually leafless stem. Fruits are achenes, white to dark, 3-4 mm long, with pappus of white toothed bristles 5-8 mm long on a beak of similar length. The leaves, stems and roots exude milky latex when damaged (Parsons and Cuthbertson, 1992).
C. juncea is a herbaceous biennial or perennial plant native to parts of Western Europe, north Africa and central Asia. It was accidentally introduced into a number of regions around the world as a contaminant of plant material, seed and fodder. C. juncea is invasive in Australia, Argentina, Canada, New Zealand, South Africa and a number of states in the USA. C. juncea produces a large tap root which can compete with native plant species for nutrients and water. In Australia and Argentina it is a major problem of wheat fields and can reduce yields by 80%. In the USA, C. juncea is one of the invasive species impacting on the threatened species Silene spaldingii. A number of distinct genotypes of C. juncea exist which makes control of this species difficult. In addition to this, C. juncea is resistant to a large number of herbicides.
In Australia and Argentina, C. juncea is a major problem of wheat fields and can reduce yields by 80%.
A. fulica is distinctive in appearance and is readily identified by its large size and relatively long, narrow, conical shell. Reaching a length of up to 20 cm, the shell is more commonly in the size range 5-10 cm. The colour can be variable but is most commonly light brown, with alternating brown and cream bands on young snails and the upper whorls of larger specimens. The coloration becomes lighter towards the tip of the shell, which is almost white. There are from seven to nine spirally striate whorls with moderately impressed sutures. The shell aperture is ovate-lunate to round-lunate with a sharp, unreflected outer lip. The mantle is dark brown with rubbery skin. There are two pairs of tentacles on the head: a short lower pair and a large upper pair with round eyes situated at the tip. The mouth has a horned mandible, and a radula containing about 142 rows of teeth, with 129 teeth per row (Schotman, 1989;Salgado, 2010). Eggs are spherical to ellipsoidal in shape (4.5-5.5 mm in diameter) and are yellow to cream in colour.
A. fulica is a large and conspicuous crop pest which hides during the day. Surveys are best carried out at night using a flashlight. It is easily seen, and attacked plants exhibit extensive rasping and defoliation. Weight of numbers can break the stems of some species. Its presence can also be detected by signs of ribbon-like excrement, and slime trails on plants and buildings.
In garden plants and ornamentals of a number of varieties, and vegetables, all stages of development are eaten, leading to severe damage in those species that are most often attacked. However, cuttings and seedlings are the preferred food items, even of plants such as Artocarpus which are not attacked in the mature state. In these plants damage is caused by complete consumption or removal of bark. Young snails up to about 4 months feed almost exclusively on young shoots and succulent leaves. The papaya is one of the main fruits which is seriously damaged by A. fulica, largely as a result of its preference for fallen and decaying fruit.
In plants such as rice, which are not targets of A. fulica, sometimes sheer weight of numbers can result in broken stems. In general, physical destruction to the cover crop results in secondary damage to the main crop, which relies on the cover crop for manure, shade, soil and moisture retention and/or nitrogen restoration. This in turn can result in a reduction in the available nitrogen in the soil and consequently marked erosion in steeper areas.
The giant African land snail A. fulica is a fast-growing polyphagous plant pest that has been introduced from its native range in East Africa to many parts of the world as a commercial food source (for humans, fish and livestock) and as a novelty pet. It easily becomes attached to any means of transport or machinery at any developmental stage, is able to go into a state of aestivation in cooler conditions and so is readily transportable over distances. Once escaped it has managed to establish itself and reproduce prodigiously in tropical and some temperate locations. As a result, A. fulica has been classified as one of the world's top 100 invasive alien species by The World Conservation Union, IUCN (ISSG, 2003).
A. fulica is a polyphagous pest. Its preferred food is decayed vegetation and animal matter, lichens, algae and fungi. However, the potential of the snail as a pest only became apparent after having been introduced around the world into new environments (Rees, 1950). It has been recorded on a large number of plants including most ornamentals, and vegetables and leguminous cover crops may also suffer extensively. The bark of relatively large trees such as citrus, papaya, rubber and cacao is subject to attack. There are reports of A. fulica feeding on hundreds of species of plants (Raut and Ghose, 1984;Raut and Barker, 2002). Thakur (1998) found that vegetables of the genus Brassica were the most preferred food item from a range of various food plants tested. However, the preference for particular plants at a particular locality is dependent primarily on the composition of the plant communities, with respect to both the species present and the age of the plants of the different species (Raut and Barker, 2002). Crops in the Poaceae family (sugarcane, maize, rice) suffer little or no damage from A. fulica.
Given the polyphagous nature of A. fulica any host list is unlikely to be comprehensive. Those plant hosts included in this datasheet have been found in literature searches and Venette and Larson (2004).
F. alnus is a deciduous shrub or small tree usually 4-5 m in height (Tutin et al., 1968), but may grow to 7 m (Gleason, 1963). It develops an erect, slender habit with branches somewhat irregular in alternate pairs, ascending at an acute angle to the main stem (Godwin, 1943). Young twigs are green but turn grey-brown with age and develop red-brown to dark violet tips. Lenticels may be evident as white dots and stripes. Lemon-yellow inner-bark tissues are exposed when the outer-bark is damaged and the young wood is dark brown. Old bark is smooth, except in very old specimens, and readily peels off dead wood. Spines are absent from F. alnus. Leaves are petiolate, obovate in shape, 2-7 cm in length and usually little more than half as wide. They are cuspidate to acuminate in shape, typically ending with a short pointed tip. Leaf margins are entire but wavy, although in seedlings leaves may be serrated. The lower surface of young leaves is pubescent, being covered with dense brownish hairs which are later shed so that older leaves are glabrous and shiny green in colour. Sun leaves are relatively broader and more shiny than shade leaves. The leaves turn yellow, then red in the autumn. Lateral veins are conspicuous on the upper surface of the leaves with 6-12 (commonly 7) pairs running more or less parallel to each other.
F. alnus develops sessile umbels in the leaf axils on young wood with 2-8 flowers borne on stout, unequal, glabrous pedicels 3-10 mm long;occasionally single flowers develop. Individual flowers are greenish-white, about 3 mm in diameter and bisexual. The flowers are 5-merous with broadly obovate petals 1-1.4 mm long and cleft at the tip (Gleason, 1963). Fruits are 6-10 mm in diameter, and change from green to red, then to violet-black on ripening;flowering and fruit development are rather asynchronous, hence all stages of ripening may be present. Each drupe usually contains 2, but occasionally 3, pyrenes or stones which are broadly obovoid in shape, about 5 mm long and 2 mm thick;they have a faint ridge running down the inner face and a deep furrow at the base. Young and Young (1992) report 52 seeds/g for F. alnus. Germination is hypogeal (Godwin, 1943).
F. alnus was introduced to North America from Europe more than 100 years ago. Once established it maintains itself due to prolific seed production, vigorous growth over an extended growing season and its ability to regenerate following burning and cutting. These characteristics make it difficult to eradicate. Repeated cutting and application of herbicides required to eliminate F. alnus is laborious and expensive. Consequently, most restoration work has been conducted in natural ecosystems of special interest. Its adverse effect on native species arises because F. alnus shades out understorey plants. Its aggressive character, especially in wetlands, is widely noted (Catling and Porebski, 1994).
F. alnus is a problem species in native communities because it establishes in dense stands which shade out other understorey species. Possessky et al. (2000) reported a reduction in composition and abundance of the herbaceous cover in riparian habitats in the northern Allegheny Plateau (of Pennsylvania, New York and Ohio, USA) following invasion by F. alnus. Similarly, Reinartz (1997) described how an undisturbed bog community in Wisconsin was invaded by F. alnus in 1955 with a dense tall shrub canopy dominating the site within 12 years. The species is listed as an invasive weed in Tennessee and Wisconsin, USA (Southeast Exotic Pest Plant Council, 1996;Hoffman and Kearns, 1997). F. alnus was recently rated as one of the six principal invasive aliens of wetlands in Canada, and one of four principal invasive aliens in Canadian uplands. In a national survey it was rated second to purple loosestrife (Lythrum salicaria) with respect to the extent to which it is spreading in natural habitats and its severity of impact in Canada (White et al., 1993).
F. alnus is associated with crown rust (Puccinia coronata) which infects several cool season turfgrasses, native grasses and cereals. The uredia, telia and basidiospores are produced on the graminoid hosts, the aecia and pycnia are produced on F. alnus (and Rhamnus cathartica;Partridge, 1998). Alfalfa mosaic virus, which infects a wide variety of plants, including crops, and is vectored by aphids, has also been isolated from young leaves and root cuttings of F. alnus in Italy (Marani and Giunchedi, 2002).
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).
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.
T. alata is considered a weed affecting mostly plantation crops such as Citrus, coffee, mango, and banana plantations (Vibrans, 2009).
L. japonica is a perennial woody climber vine, twining or clambering, much branched, 5-8 m in length. Stems strong, flexible, cylindrical, pilose, brown, smooth. Leaves opposite;blades 4-7.5 × 1.2-3 cm, lanceolate, oblong-lanceolate, or elliptic-lanceolate, chartaceous, glabrous except for some hairs on the midvein, the apex acute or obtuse, abruptly acuminate or mucronate, the base rounded, subtruncate, or obtuse, the margins entire revolute, ciliate;upper surface dark green, dull;lower surface pale green, dull, with a prominent midvein;petioles 5-12 mm long, brown, pubescent. Flowers fragrant, sessile, in pairs at the end of short axillary branches;bracts 2, at the base of each flower, ovate, rounded, ca. 0.7 mm long, ciliate. Calyx green, tubular, ca. 3 mm long, the sepals 5, subulate, ca. 1 mm long;corolla white, turning yellowish when mature, 2.2-2.5 cm long, infundibuliform, the tube puberulous outside;the limb with 5 lobes, one of which is longer (ca. 2.2 cm) and free;stamens 4, exserted;style exserted, with the stigmatic surface claviform (Acevedo-Rodriguez, 2005). Fruits are sessile berries, 0.4-0.7 cm in diameter, hard and green when immature, and black and soft (even fluid-filled) when ripe. Fruits contain two or three seeds that are approximately 0.2 cm in diameter, ovate to oblong, with a flat to concave inner surface and three ridges on the dorsal surface.
L. japonica is an aggressive vine which develops into a smothering mass of belowground runners and aboveground intertwined stems that cover extensive areas of the ground or climb up trees for many metres. It interferes with forestry operations and orchards and smothers native vegetation, preventing natural successional processes by killing or weakening young trees and preventing seedling regeneration. The fleshy fruit are spread by birds and animals, and runners go for long distances underground. It cannot be controlled simply by hand, but herbicides are moderately effective.
L. japonica smothers other plants at all growth stages, i.e. it covers bare ground (pre-emergence) right through to occupying cut-over (post harvest) forests.
Schiefer and Bright (2004) provide a thorough detailed description of the female. The males are relatively scarce. In comparison with other members of the tribe Xyleborini, X. mutilatus is relatively large at 3.46-3.88 mm long (Schiefer and Bright, 2004). The adult beetles are black, with reddish-brown legs and antennae. The elytra are 0.78 times longer than they are wide (Schiefer and Bright, 2004) and appear shorter than the pronotum, making them readily recognisable (Thomas, 2007). In dorsal view, the head is completely hidden by the pronotum, which is 0.86 times longer than it is wide and 1.11 times longer than the elytra (Schiefer and Bright, 2004;Coyle, 2006). The antennal club is round and appears to be obliquely cut (Coyle, 2006;Thomas, 2007). The body is generally smooth and shining (Coyle, 2006), with a long, golden and moderately dense pubescence on the abdomen (Schiefer and Bright, 2004).
Ambrosia beetles construct galleries (tunnels) in the xylem wood of their host plants, wherein the adults and larvae will be found with their fungal associates and accompanying staining of the wood. External evidence of Xylosandrus presence will be pin-hole sized entrance wounds in the bark that may be either bleeding or contain a light colored boring dust. There may be tooth-pick-like curling frass at the entrance holes (Rabaglia, 2003). Attacked plants may be wilting, exhibiting twig dieback, or dead. Often such plants are of small diameter, less than 5 cm.
X. mutilatus is a polyphagous ambrosia beetle, of possible relevance as a pest, that is indigenous to at least 10 countries in eastern and southern Asia (Japan to India). It has been recently discovered (1999) in the warm temperate, southeastern United States (Alabama, Georgia, Florida, Mississippi, Tennessee, and Texas), the only region occupied outside of its native Asian range. In northern Mississippi, it has multiplied prolifically and appears therefore highly capable of surviving and spreading in its newly adopted territory.
In its natural range, reported hosts of X. mutilatus are as follows (Schiefer and Bright, 2004): Acer spp. Acer sieboldianum Albizia spp. Benzoin [ Lindera ] spp. Camellia spp. Carpinus laxiflora Castanea spp. Cinnamomum camphora Cornus spp. Cryptomeria japonica Fagus crenata Lindera erythrocarpa Lindera triloba Machilus thunbergii [ Persea thunbergii ] Ormosia hosiei Osmanthus fragrans Parabenzoin praecox [ Lindera praecox ] Platycarya spp. Swieitenia macrophylla.
In North America, reported hosts of X. mutilatus are as follows (Stone et al., 2007):
Acer palmatum Acer rubrum Acer saccharum Carya spp. Juglans nigra Liquidambar styraciflua Liriodendron tulipifera Melia azedarach Ostrya virginiana Pinus taeda Prunus serotina Prunus americana Ulmus alata
Host Plants and Other Plants Affected
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Acer palmatum (Japanese maple)|Aceraceae
Acer rubrum (red maple)|Aceraceae
Acer saccharum (sugar maple)|Aceraceae
Cinnamomum camphora (camphor laurel)|Lauraceae
Cryptomeria japonica (Japanese cedar)|Taxodiaceae
Fagus crenata (Japanese beech)|Fagaceae
Juglans nigra (black walnut)|Juglandaceae
Liquidambar styraciflua (Sweet gum)|Hamamelidaceae
Liriodendron tulipifera (tuliptree)|Magnoliaceae
Melia azedarach (Chinaberry)|Meliaceae
Ostrya virginiana (American hophornbeam)|Betulaceae
Pinus taeda (loblolly pine)|Pinaceae
Prunus americana (American plum)|Rosaceae
Prunus serotina (black cherry)|Rosaceae
Swietenia macrophylla (big leaved mahogany)|Meliaceae
Ulmus alata (Winged elm)|Ulmaceae
Vitis rotundifolia (Muscadine grape)|Vitaceae
List of Symptoms/Signs
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Stems / dieback
Stems / discoloration
Stems / internal discoloration
Stems / internal feeding
Stems / mycelium present
Stems / necrosis
Stems / ooze
Stems / visible frass
Whole plant / discoloration
Whole plant / frass visible
Whole plant / internal feeding
Whole plant / plant dead;dieback
Biology and Ecology
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X. mutilatus is univoltine. Adult females make dispersal flights from June to August, seeking small diameter hosts in which to establish a gallery in the wood. Reported host plants in its natural range include Acer spp., Acer sieboldianum, Albizia spp., Benzoin [ Lindera ] spp., Camellia spp., Carpinus laxiflora, Castanea spp., Cinnamomum camphora, Cornus spp., Cryptomeria japonica, Fagus crenata, Lindera erythrocarpa, Lindera triloba, Machilus thunbergii [ Persea thunbergii ], Ormosia hosiei, Osmanthus fragrans, Parabenzoin praecox [ Lindera praecox ], Platycarya spp., and Swieitenia macrophylla (Schiefer and Bright, 2004). In North America its reported hosts thus far include Acer rubrum, Acer saccharum, Acer palmatum, Carya spp., Liriodendron tulipifera, Liquidambar styraciflua, Melia azedarach, Ostrya virginiana, Pinus taeda, Prunus serotina, Prunus americana, Ulmus alata, and Vitus rotundifolia (Stone et al., 2007). The gallery system excavated in the xylem is inoculated with spores of several species of ambrosia fungi (Kajimura and Hijii, 1992;Stone et al., 2005) carried in mycangia, a pair of dorsally located pits between the pronotum and mesonotum. As many as 38 eggs (average is 10) are laid per gallery. The female guards the gallery entrance and will block the entrance hole with her body as a defence against enemies. However, little has been reported about the nature and importance of natural enemies of X. mutilatus. Egg hatch begins about 7 days post oviposition and the larvae feed on the mycelia of the ambrosia fungi. Larvae are c-shaped and cream colored, without legs. Pupation occurs 2-3 weeks later, and adults emerge after about 1 week (Rabaglia, 2003;Schiefer and Bright 2004). As is typical of many ambrosia beetles, X. mutilatus has inbred polygamy. Mating occurs within the gallery immediately after eclosion. Only one to three males develop in each gallery where they remain and mate with their sisters. Males die after mating, and the females overwinter within the natal gallery (Rabaglia, 2003;Schiefer and Bright, 2004).
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).
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).
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).
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).
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.
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).
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).
Male adults are 24 to 46 mm long and females 57 to 66 mm long (Barrientos-Lozano, 2003). The medial pronotal carina is cut by three transversal sulcus;the posterior femur has black dots on the external upper part. The prosternal tuberculum is straight and smaller than in S. pallens. Nymphs and young adults possess a mild subocular fringe.
North American S. nitens can be characterized by tectiform pronotum and mottled tegmina.
S. nitens (Thunberg) is a short-horned grasshopper classified in the Family Acrididae. It is native to southwestern North America, Central America and northern South America. It was first reported as invasive in the Hawaiian archipelago in 1964 and is now present on all the main Hawaiian islands. S. nitens is solitary and non-migratory, but under certain conditions can form swarms or outbreaks and cause damage to crops and native plant species. In 2002 and 2004 outbreaks on the Hawaiian island of Nihoa posed a threat to all the vegetation on the island, particularly endangered plant species.
Richman et al. (1993) and Dirsh (1974) reported damage to Gossypium herbaceum (cotton), Medicago sativa (alfalfa), citrus and Musa acuminata (banana). Salas-Araiza et al. (2003) reported Casuarina sp., Helianthus sp., and Schinus sp. as plant hosts of S. nitens in Guanajuato, Mexico. In Hawaii, damage to sugarcane has been reported (Bowler et al., 1977). Dirsh (1974) reported cotton Gossypium sp. and alfalfa Medicago sativa as hosts of S. nitens. Latchininsky (2008) is one of the references that reported the plant species affected in the 2002-2004 outbreak in Nihoa Island, Hawaii.
USDA-ARS (1993) published a profile of S. nitens and reported plants in the Family Phorbeaceae, sugarcane and grapes as the most affected by S. nitens in New Mexico, USA. In California, S. nitens is a pest of grapes (Winkler et al., 1974). Cano-Santana et al. (2006) reported Croton as host plant on Isla Socorro, Revillagigedo Islands, Mexico.
Bianchi (1964) reported Ananas comosus (pineapple) and sugarcane Saccharum officinarum leaves as hosts in Hawaii.
A cactus-like, usually leafless but evergreen shrub or small tree up to 5 metres high and 15-20 cm in trunk diameter, with fleshy or succulent stems, much branched, hairless throughout, producing abundant milky sap when injured. Stems with whorls of branches nearly to base but on large plants shedding the spiny tissue and developing a rounded brown, fissured trunk. The 3-angled (sometimes 4-angled) branches are mostly joints 10-30 cm long and 2-5 cm across, slightly shiny dark green, with yellowish or whitish streak in the groove of the axis between the angles. The soft cut branches have a light green outer layer less than 0.5 cm thick, which yields latex, and within whitish watery tissue, slightly bitter. Raised leaf bases 0.5 cm high and about 1-2.5 cm apart along the edges of branches correspond to nodes and bear paired spreading gray spines (stipules). Leaves few, scattered, alternate, minute, stalkless, rounded, slightly shiny green, succulent, slightly thick and shedding early, or absent. Flowers small, yellowish green, borne intermittently in small clusters along the stem’s edge (Little et al., 1974).
E. lactea has been widely commercialized as an ornamental plant and due to the presence of spines it is also used as a fence/hedge plant. Many cultivars have been developed for the horticultural trade (USDA-ARS, 2016). It has escaped from cultivation and once naturalized, it often grows forming thickets mostly in disturbed sites, abandoned gardens, deciduous forests, coastal forests, and along roadsides (Little et al., 1974;PIER, 2016;PROTA, 2016). E. lactea spreads by seeds and vegetatively by cuttings and stem fragments (Little et al., 1974). Currently, this species is listed as invasive in Hawaii and Cuba (Oviedo Prieto et al., 2012;PIER, 2016). In Puerto Rico and the Virgin Islands, it is spreading and forming thickets in some places (Little et al., 1974).
Description of P. ligularis adapted from Morton (1987), Holm-Nielsen et al. (1988), Davidse et al. (1994), Wagner et al. (1999), Mendes Ferrão (2002), Rodriguez (2007), Hyde et al. (2016) and Duarte and Paull (2015).
P. ligularis is most likely to be imported as seed, but also as cuttings or seedlings. Seeds may be difficult to identify, though seedlings and leafy cuttings should be identifiable by leaf characters.
P. ligularis is a vigorous climbing plant native to Mexico, Central America and northwest South America south to Bolivia. Valued for its edible fruit (second only to P. edulis) and ornamental flowers, it is commonly cultivated and has often escaped in the tropical highlands of Central and South America. P. ligularis has been introduced and cultivated in India, east and southeast Asia, Australia and New Zealand and several Pacific islands, and is invasive in Haiti, Jamaica, Hawaii, Singapore, Indonesia, Zimbabwe, the Galapagos Islands and Samoa. In New Caledonia it is a declared noxious weed and its introduction is prohibited. P. ligularis can impact farming by smothering vegetation and impeding access, and may be poisonous or unpalatable to livestock. It also invades natural mesic forests and other natural vegetation formations, where it can shade out understorey plants.
Cherimoyas are erect trees, 3-10 m tall, often low-branched and somewhat shrubby or spreading. The briefly deciduous to semi-deciduous (just before spring flowering) leaves are ovate to ovate-lanceolate, sometimes obovate or elliptical, 12-20 cm x 8 cm, persistently brownish velvety-tomentose beneath. They are alternate, 2-ranked, with minutely hairy petioles, slightly hairy on the upper surface, velvety on the underside. Flowers are fragrant, extra-axillary, often opposite a leaf at the base of a branchlet, usually solitary but sometimes two or three grouped together on short nodding tomentose peduncles;outer three tepals oblong-linear, up to 3 cm long, greenish to pale yellow, marked with a purple spot at the base within;inner three tepals very small, reddish to purplish;androecium consisting of numerous free fleshy stamens, spirally arranged on the basal part of a conical receptacle;gynoecium comprising numerous free pistils on the upper part of the receptacle. Fruit is a syncarp or pseudocarp formed by the fusion of the carpels and the receptacle into a fleshy mass, variable in shape and appearance, from heart-shaped with surface bearing protuberances to spheroid or ovoid with the surface covered with 'U'-shaped areoles or rather smooth, 10-20 cm long and up to 10 cm in width, weighing on average 150-500 g, but extra large specimens of 2.7 kg or more have been reported;pulp white, edible, easily separable from the seeds. The skin may be smooth with fingerprint-like markings or covered with conical or rounded protuberances. The fruit is easily broken or cut open, exposing the snow-white, juicy flesh of pleasing aroma and delicious, subacid flavour. It contains numerous hard, brown or black, bean-like, glossy seeds, 1.25-2 cm long. The fruit is composed of an exocarp (fruit skin), occupying between 15 and 25% on a weight basis, an edible mesocarp (pulp and thalamus), varying between 65 and 80%, and seeds, ranging from 3 to 10%. Seeds usually obovate, obliquely truncate, somewhat compressed, with a thin, membranous, brown, wrinkled testa.
A. cherimola is a tree of American origin that has been cultivated in tropical and temperate regions around the world for its edible fruit. It is listed as a “cultivation escape, environmental weed, naturalised, weed” in the Global Compendium of Weeds (Randall, 2012) and is known to be invasive in places both within and beyond its native range including Easter Island, the Galapagos, Hawaii, and New Zealand (PIER, 2014). A risk assessment gave the species a low invasive risk score of -4, but excluded several invasive traits in this score such as its known status as a garden/agricultural/environmental weed and naturalization beyond its native range (PIER, 2014). The species reproduces by seeds but can be propagated by grafting (Janick and Paull, 2008).
Perennial, prostrate, slender, creeping herb, the often purplish stems rooting at the nodes and often forming mats. Leaves are ovate, 1-4 cm long;1-2 cm broad, acute at apex, rounded to sub-cordate at base, sessile, sub-succulent, glabrous except for ciliate margins;pale green;sheath tubular, 3-3.5 mm long, with a few long hairs at apex. Flowering in branches often somewhat ascending with leaves progressively smaller;flowers-clusters barely exserted beyond the sheaths in leaf-axils;bracts filiform, ciliate, 6-7 mm long. Sepals 3, linear lanceolate, greenish, 2-5 mm long, minutely pubescent;petals 4, oblong, whitish hyaline, slightly shorter than or equaling the sepals;stamens exserted, typically 3, but may vary in number from 0 to 6;filaments minutely ribbon-like, coiled at first, to 10 mm long;anthers rounded-elliptic or elliptic, basal on a reniform white connective ca. 0.5 mm long. Ovary 2-locular, pilose at apex, style filiform, up to 4.5 mm long, the stigma trifid (Howard, 1979) or penicillate (Hunt, 1983), 2 ovules per locule. Fruit is a lenticular capsule, approximately 1.7 mm long, splitting from apex to base;seeds 2 per valve, brown, approximately 1 mm, rugose (Acevedo-Rodríguez and Strong, 2005).
C. repens is an herbaceous species which has been widely cultivated as an ornamental in gardens and yards in tropical and subtropical regions from where it has escaped into natural areas. C. repens spreads vegetatively by cuttings, plant fragments, and/or discarded plants (Acevedo-Rodríguez and Strong, 2005). Once established, this species grows forming dense groundcover or “beds” on the forest floor preventing the germination and establishment of native plants. C. repens is listed as an invasive in South Africa, China, and Cuba (Foxcroft et al., 2007;Flora of China Editorial Committee, 2012;González-Torres et al., 2012), and it is also a common weed in Puerto Rico and US Virgin Islands (Más and Lugo, 2013).
Cutting is the separation or opening of a physical object, into two or more portions, through the application of an acutely directed force.
Implements commonly used for cutting are the knife and saw, or in medicine and science the scalpel and microtome. However, any sufficiently sharp object is capable of cutting if it has a hardness sufficiently larger than the object being cut, and if it is applied with sufficient force. Even liquids can be used to cut things when applied with sufficient force (see water jet cutter).
Cutting is a compressive and shearing phenomenon, and occurs only when the total stress generated by the cutting implement exceeds the ultimate strength of the material of the object being cut. The simplest applicable equation is:
The stress generated by a cutting implement is directly proportional to the force with which it is applied, and inversely proportional to the area of contact. Hence, the smaller the area (i.e., the sharper the cutting implement), the less force is needed to cut something. It is generally seen that cutting edges are thinner for cutting soft materials and thicker for harder materials. This progression is seen from kitchen knife, to cleaver, to axe, and is a balance between the easy cutting action of a thin blade vs strength and edge durability of a thicker blade.