Aleurodicus dispersus

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Aleurodicus dispersus
Aleurodicus dispersus (Russell) - spiral whitefly (characteristic waxy secretions) - 3762764050.jpg
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hemiptera
Suborder: Sternorrhyncha
Family: Aleyrodidae
Genus: Aleurodicus
Species:
A. dispersus
Binomial name
Aleurodicus dispersus
Russell, 1965

Aleurodicus dispersus, the spiralling whitefly, is a species of small, white sap-sucking insect, a true bug in the order Hemiptera. It originated in Central America and the Caribbean region and has spread to many of the world's tropical and subtropical regions, where it has become a major pest of agricultural crops.

Contents

Description

Adult spiralling whitefly are small, white, moth-like insects some 1/12-1/8 inch (2–3 mm) long. When they emerge from the pupal casing, the wings are transparent, but they soon become dusted with white fragments of wax. Each of the forewings bear a characteristic pair of black spots and the eyes in this species are a dark reddish brown. [1]

Distribution

Aleurodicus dispersus is native to Central America and the Caribbean but is not regarded as a pest species in these areas. [2] Since the middle of the 20th century it has spread to many parts of the tropics and subtropics. [3] It was found and intercepted in the 1950s on imports into the United States by quarantine officials but later became established in Florida and in 1962 it had reached the Canary Islands. In the early 1980s it had appeared in Hawaii and other Pacific islands and had spread across tropical Asia by the middle of the decade. It had extended its range by the early 1990s to West Africa and India and to parts of the Indian Ocean. In 2009 it was still absent from the Mediterranean region, the Middle East, Hong Kong and most of Australia. [3] It is most common at altitudes of less than 1000 feet (300 metres). [1]

Biology

Aleurodicus dispersus is polyphagous, meaning that it is not reliant on a single host food plant but can feed on many different species of plant. [4] Its host range includes over 100 species in 38 genera and 27 families. [2] Cultivated crops and ornamentals affected by it include banana, coconut, citrus, avocado, breadfruit, mango, macadamia, guava, paw-paw, capsicum, lead tree, frangipani and rose. [2]

The life cycle starts with the deposition of a number of eggs that vary in colour from yellow to tan. These are laid, interspersed with bits of wax, in the form of a spiral on the surface of a leaf, usually on the underside. The eggs hatch after around ten days and pass through four immature stages before becoming adults. The first stage is known as a "crawler" and can move around while the other stages are sedentary. Once settled on the leaf surface, the nymphs start to exude tufts of white wax on the dorsal surface and the third stage nymph additionally produces glass-like waxy rods on its lateral surfaces, which may grow to a length of 0.3 in (8 mm) but usually break off before they reach this length. The first three stages feed by sucking sap from the plant whilst the fourth stage only does so initially, later becoming a puparium while undergoing some internal reorganisation of its tissues. [1] [5]

The adults disperse by flying [5] and females start laying eggs within about one day after emerging from their pupal cases. Unmated females produce exclusively male offspring whereas mated females produce young of both sexes. In the laboratory, the maximum lifespan was found to be 39 days, with 20 pairs of spiralling whitefly producing a total number of 1549 progeny over the course of 37 days. [2]

Crop damage

The spiralling whitefly may cause damage to crops in several ways. The feeding of the adults, and particularly the sucking of sap by the first three nymphal stages, weakens the plant and causes leaves to fall prematurely, but is seldom sufficient to kill the plant. The copious amounts of honeydew secreted by the insects is appreciated by ants, wasps, bees and other insects and these may protect the whitefly from predation. Sooty mould often grows on the honeydew and may reduce the leaf area available for photosynthesis, disfigure the plant and even make it unmarketable. The nymphs produce a flocculent white waxy material and this may be dispersed by the wind and create "an unsightly nuisance". The spiralling whitefly can act as a vector and is one of only three species of whitefly able to transmit plant viruses. In some cases, these may cause the complete loss of the crop. [1]

Pest status

Aleurodicus dispersus is considered to be a major agricultural pest. [6] Despite the application of quarantine measures it has spread rapidly in the tropics and caused the loss of many millions of dollars through lower crop yields. Biological control by the introduction of predators such as ladybirds and parasitic wasps has proved quite effective. When a new area is invaded, at first the whitefly flourish unchecked, but in the course of time, the predators begin to exert some control and populations become more stable and start to reduce. [6]

Related Research Articles

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Hemiptera is an order of insects, commonly called true bugs, comprising over 80,000 species within groups such as the cicadas, aphids, planthoppers, leafhoppers, assassin bugs, bed bugs, and shield bugs. They range in size from 1 mm (0.04 in) to around 15 cm (6 in), and share a common arrangement of piercing-sucking mouthparts. The name "true bugs" is often limited to the suborder Heteroptera.

<span class="mw-page-title-main">Whitefly</span> Family of insects

Whiteflies are Hemipterans that typically feed on the undersides of plant leaves. They comprise the family Aleyrodidae, the only family in the superfamily Aleyrodoidea. More than 1550 species have been described.

<span class="mw-page-title-main">Scale insect</span> Superfamily of insects

Scale insects are small insects of the order Hemiptera, suborder Sternorrhyncha. Of dramatically variable appearance and extreme sexual dimorphism, they comprise the infraorder Coccomorpha which is considered a more convenient grouping than the superfamily Coccoidea due to taxonomic uncertainties. Adult females typically have soft bodies and no limbs, and are concealed underneath domed scales, extruding quantities of wax for protection. Some species are hermaphroditic, with a combined ovotestis instead of separate ovaries and testes. Males, in the species where they occur, have legs and sometimes wings, and resemble small flies. Scale insects are herbivores, piercing plant tissues with their mouthparts and remaining in one place, feeding on sap. The excess fluid they imbibe is secreted as honeydew on which sooty mold tends to grow. The insects often have a mutualistic relationship with ants, which feed on the honeydew and protect them from predators. There are about 8,000 described species.

<span class="mw-page-title-main">Silverleaf whitefly</span> Species of true bug

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<span class="mw-page-title-main">Eriosomatinae</span> Subfamily of aphids

Woolly aphids are sap-sucking insects that produce a filamentous waxy white covering which resembles cotton or wool. The adults are winged and move to new locations where they lay egg masses. The nymphs often form large cottony masses on twigs, for protection from predators.

<span class="mw-page-title-main">Greenhouse whitefly</span> Species of true bug

Trialeurodes vaporariorum, commonly known as the glasshouse whitefly or greenhouse whitefly, is an insect that inhabits the world's temperate regions. Like various other whiteflies, it is a primary insect pest of many fruit, vegetable and ornamental crops. It is frequently found in glasshouses (greenhouses), polytunnels, and other protected horticultural environments. Adults are 1–2 mm in length, with yellowish bodies and four wax-coated wings held near parallel to the leaf surface.

<i>Psylla pyri</i> Species of true bug

Psylla pyri, commonly known as the pear psylla or pear psyllid, is an insect in the family Psyllidae. Originating in Europe and Asia, it has spread to North America. It is a pest of pear trees, sucking the sap, damaging the foliage, flowers and fruit and diminishing the crop.

<i>Aleurocanthus woglumi</i> Citrus pest from India, now worldwide

Aleurocanthus woglumi is a species of whitefly in the family Aleyrodidae. It is a pest of citrus crops, and is commonly known as the citrus blackfly because of its slate-blue colour. It originated in Asia, but has spread to other parts of the world. The parasitic wasps, Encarsia perplexa and Amitus hesperidum can help control the pest.

<i>Paracoccus marginatus</i> Species of true bug

Paracoccus marginatus, commonly known as the papaya mealybug, is a small sap-sucking insect in the mealybug family, Pseudococcidae. It is found on a number of different hosts, including economically important tropical fruit trees and various ornamental plants.

<i>Metcalfa pruinosa</i> Species of planthopper

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<i>Coccus hesperidum</i> Species of true bug

Coccus hesperidum is a soft scale insect in the family Coccidae with a wide host range. It is commonly known as brown soft scale. It has a cosmopolitan distribution and feeds on many different host plants. It is an agricultural pest, particularly of citrus and commercial greenhouse crops.

<i>Eriosoma lanigerum</i> Species of true bug

Eriosoma lanigerum, the woolly apple aphid, woolly aphid or American blight, is an aphid in the superfamily Aphidoidea in the order Hemiptera. It is a true bug and sucks sap from plants.

<i>Pulvinaria regalis</i> Species of true bug

Pulvinaria regalis is a species of scale insect in the family Coccidae. Although it is commonly known as the horse chestnut scale, it affects other trees besides horse chestnuts as well as many species of woody shrubs. Adults are normally all female and produce eggs by parthenogenesis. The insects are thought to have originated in Asia but arrived in Europe in the second half of the twentieth century.

Pyrilla perpusilla, commonly known as the sugarcane planthopper, is a planthopper in the family Lophopidae. It is native to Asia where it feeds on grasses and other plants and is a major pest of sugarcane and sorghum.

<i>Phenacoccus solenopsis</i> Species of true bug

Phenacoccus solenopsis, the cotton mealybug or solenopsis mealybug, is a species of mealybug in the family Pseudococcidae. Having originated in North America, it has spread to other parts of the world and become a major pest of cotton crops.

Aleurotrachelus atratus better known as the palm-infesting whitefly is an invasive species that affects coconut palms. Originally, this species was only prevalent in Brazil and was known to feed on coconuts native to this country. Now, the species has migrated to the tropics and subtropics and is invasive in many other countries. Aleurotrachelus is one of the largest genus, containing 74 species.

Aleurodicus cocois, commonly known as the coconut whitefly, is a species of whitefly in the family Aleyrodidae; it feeds on coconut and other palm trees in South America and the Caribbean region.

Axinoscymnus puttarudriahi, is a species of lady beetle native to India and Sri Lanka.

<i>Planococcus ficus</i> Species of mealybug

Planococcus ficus, commonly known as the vine mealybug, is a species of mealybug, belonging to the family Pseudococcidae, native to tropical and subtropical regions. The vine mealybug is found in Europe, Northern Africa, Southern Africa, the Americas, and the Middle East. The vine mealybug is invasive to weedy plants in many different regions of the world.

<i>Orchamoplatus citri</i> Species of whitefly

Orchamoplatus citri, commonly known as the Australian citrus whitefly, is a whitefly species in the genus Orchamoplatus. It is found across Australia and New Zealand, primarily foraging on the leaves of citrus trees.

References

  1. 1 2 3 4 Jayma L. Martin Kessing; Ronald F.L. Mau (1993-01-01). "Aleurodicus dispersus Russell: Spiraling Whitefly". Crop Knowledge Master. Retrieved 2014-04-20.
  2. 1 2 3 4 Waterhouse, D. F.; Norris, K. R. (1989). Biological control: Pacific prospects (Supplement 1): Aleurodicus dispersus Russell (PDF). pp. 12–24.
  3. 1 2 Martin, Jon. "Aleurodicus dispersus (spiralling whitefly): Habitat and distribution". Natural History Museum. Retrieved 2014-04-20.
  4. Martin, Jon. "Aleurodicus dispersus (spiralling whitefly)". Natural History Museum. Retrieved 2014-04-20.
  5. 1 2 Martin, Jon. "Aleurodicus dispersus (spiralling whitefly): Biology". Natural History Museum. Retrieved 2014-04-20.
  6. 1 2 Martin, Jon. "Aleurodicus dispersus (spiralling whitefly): Pest management". Natural History Museum. Retrieved 2014-04-20.