Aleurothrixus floccosus

Aleurothrixus floccosus (Maskell)

Taxonomic placing: Insecta, Hemimetabola, Hemiptera, Sternorrhyncha, Aleyrodidae.

Common name: Woolly whitefly.

Geographical distribution: The pest, which is of Asian origin, has spread to Central and North America and then to the Mediterranean region. In Israel it has been present since the early 1990’s. CIE Map #327, 1997 (revised).

Morphology: The woolly whitefly is approximately 1.5 mm in length, with a yellow-white body and wings that are covered with a white waxy powder. The legless nymphs are initially green, later becoming brownish. The pupa is covered by very conspicuous waxy (“woolly”) filaments.

Host plants: Plants in about 20 families; citrus is the main crop affected.

Economic importance: The damage of the woolly whitefly to citrus is mostly due to the large amounts of honeydew excreted by the nymphs. This honeydew serves as substrate for sootymold fungi whose dark layers interfere with leaf photosynthesis and thus with tree growth and performance. During heavy infestations the leaves attain a white-black appearance (Figure), due to the intermittent occurrence of adults and sooty mold.

Life cycle: Woolly whiteflies deposit their eggs, which are often placed in a circle or a semi-circle, into the underside of young, fully-extended leaves, usually in the inner regions of the trees. In the Mediterranean area the pest completes 5-6 annual generations, its numbers peaking during mid-summer.


Sampling: An index of occupation (from 0 to 10) was linearly related to the proportion of leaf undersurface occupied by the pest, thus being a reliable and time-saving sampling method. Examining 150 leaves achieves the desired the relative variation level of 0.25 for most population densities found in Spanish commercial citrus groves.

Biological control: The pest is usually controlled by the introduced endoparasitoid Cales noacki. Another important natural enemy is the predator Delphastus catalinae.


Argov, Y. 1994. The woolly whitefly, a new pest in Israel. Alon Ha’notea 48: 290-292 (in Hebrew with an English abstract).

Soto, A., Ohlenschlaeger, F. and Garcia-Mari, F. 2002. Distribution and sampling of the whiteflies Aleurothrixus floccosus, Dialeurodes citri and Parabemisia myricae (Homoptera : Aleyrodidae) in citrus in Spain. Journal of Economic Entomology 95: 167-173.

Ulusoy M.R., Vatansever, G., Erkilic, L. and Uygun, N. 2003. Studies on _Aleurothrixus floccosus _(Maskell) (Homoptera, Aleyrodidae) and its parasitoid, Cales noacki Howard (Hymenoptera, Aphelinidae) in the East Mediterranean region of Turkey. Anzeiger für Schadlingskunde 76: 163-169.