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Aleurothrixus floccosus Maskell
Insecta, Homoptera, Aleyrodidae .

Woolly whitefly

Description, Biology, Life Cycle, Damage, Common Names, Images

- Adult: 1.5 mm long, resembling a very small moth; with a yellow body dusted with white waxen powder, and narrow wings revealing the abdomen.
- Egg: pedunculate, oval-shaped: eggs are laid in a circle or semi-circle. (*) .
- Nymph: sedentary, with a flattened nearly transparent body protected by a mass of waxy strands and with a slightly oval shape.(*) .

- Insect infesting Citrus. Mandarin trees are particularly prone to attack (*) .
- First observed in 1966 in Spain (Malaga) and France (Côte d'Azur), this whitefly was first reported in Italy in 1980.
- Adults and nymphs feed on the sap of foliage.
In contrast with the citrus whitefly (Dialeurodes citri) the honeydew produced in large amounts by the insect continues to adhere to its body (*) .

[R]Life Cycle
- Four to five generations of the woolly whitefly succeed each other with practically no interruptions throughout the year. A slight slowing in reproduction is noted during the colder months.
- It overwinters as a 3rd or 4th nymphal instar or sometimes as eggs laid in November.
In February-March, the first flights are noted as a forerunner to the first eggs being laid. Another marked emergence usually occurs during August.
In the autumn the undersides of leaves are encrusted with nymphs and exuviae coated with honeydew (*) .
Depending on the climatic conditions, another generation may occur in October.
Because it has no enemies, this pest is found in very large populations, the only limit being the availability of food material.

- Direct damage results from the sucking of sap, this being aggravated by the intensive development of sooty moulds. Blemishes are also very widespread.

Biological control using an entomophagous hymenopteran Cales noacki (*) (*) , introduced from South America, produces very good results if its action is complemented by that of another parasite: Amitus spiniferus (from Peru), better adapted to summer heat.
Attention should also be paid to various predators: the scale insects Clitosthetus arcuatus Rossi and Chilocorus bipustulatus L. as well as Chrysopa (insects of the order Neuroptera).

[R]Common Names
DE: Wollige Zitrusmottenschildlaus ES: Mosca blanca algodonosa FR: Aleurode floconneux des citrus IT: Mosca bianca fioccosa degli agrumi PT: Mosca branca dos citrinos GB: Woolly whitefly

[R] Images

  1. Aleurothrixus floccosus (Maskell) (Coutin R. / OPIE)
    Colony On the underside of leaves of orange.
  2. Aleurothrixus floccosus (Maskell) (Coutin R. / OPIE)
    Detailed picture of a colony on leaf of orange Winged adults, young nymphs and older "pupae", frothy secretions and droplets of honeydew.
  3. Aleurothrixus floccosus (Maskell) (Onillon J.-P. / INRA Antibes)
    Parasitized "pupae" It is possible to distinguish the exit aperture of the parasite Cales noacki (Hymenoptera).
  4. Aleurothrixus floccosus (Maskell) (INRA Antibes)
    Cales noacki laying eggs in a "pupa"
  5. Aleurothrixus floccosus (Maskell) (Daumal J. / INRA Antibes)
    Nymphs excreting honeydew 2nd-stage nymphs.
  6. Aleurothrixus floccosus (Maskell) (Daumal J. / INRA Antibes)
    4th-stage nymphs cleared of honeydew
  7. Aleurothrixus floccosus (Maskell) (INRA)
    Eggs arranged in a circle

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HYPPZ on line : Species (scientific name), Pests (common names), Glossary, Crops.

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