Common name: Whiteflies.
Geographical distribution: World-wide, with more than 1,500 described species.
Morphology: Whiteflies are small (2-3 mm long) insects, with membranous wings whose venation is much reduced and their bodies are covered with whitish mealy flakes (hence the vernacular name). The legs are well developed and the antennae have seven segments. The honeydew-excreting organ (the “vasiform orifice”) is located dorsally on the posterior part of the pre-adult and adult body. The juveniles (except the crawler) are flat-bodied, immobile, lack legs and are covered with translucent wax; the molting, pre-adult stage (often called “puparium” is covered with characteristic wax filaments. The eggs have stalks that may exceed the length of the egg.
Life cycle: The stalked eggs are inserted into the tissue of the host plant with some wax left around; due to the spiral movement of the female during oviposition the eggs may be placed around it in a circle. The crawlers often settle near their mothers where they remain stationary till becoming adults. The common pest species raise a generation in 3-4 weeks, producing 100-200 eggs/female; reproduction is usually by arrhenotoky. The adults fly about (often in a “cloud”) and thus disperse their eggs and transmit plant viruses.
Economic importance: This family contains several major pests, whose damage is due to sucking host plant phloem and to excreting large amounts of honeydew, which is colonized by sootymold fungi. These fungi cover fruits and leaves by a thick black mass and hinder photosynthesis, and may also spoil cotton lint. In addition, several species disseminate plant viruses as well as another plant pest, the broad mite, Polyphagotarsonemus latus.
Chemical control: Pest whiteflies can be controlled by IGRs.
Symposia on whiteflies and their control can be accessed at: http://www.whitefly.org/EWSII-Program.asp
Whitefly pests included in this compendium
Abd-Rabou, S. 1997. Key to the species of whiteflies from Egypt (Homoptera: Aleyrodidae). Bulletin of the Entomological Society of Egypt. 75: 38–48.
Gerling, D. (ed.) 1990. Whiteflies: Their Bionomics, Pest Status and Management. Intercept, Andover, UK.
Gerling, D., Guershon, M. and Seplyarsky, V. 2016. Whiteflies of Israel. Plant Protection and Inspection Services, Ministry of Agriculture and Rural Development, Israel, 112 pp.
Martin, J.H. and Mound, L.A. 2007. An annotated check list of the world’s whiteflies (Insecta: Hemiptera: Aleyrodidae). Zootaxa 1492: 1–84.
Ovall, T.M., Parsa, S., Hernández, M.P. and Becerra Lopez-Lavalle, L.A. 2014. Reliable molecular identification of nine tropical whitefly species. Ecology and Evolution 4: 3778-3787.
Palevsky, E., Soroker, V., Weintraub, P., Mansour, F., Abu-Moach, F. and Gerson, U. 2001. How species-specific is the phoretic relationship between the broad mite, Polyphagotarsonemus latus (Acari: Tarsonemidae), and its insect hosts? Experimental and Applied Acarology 25: 217-224.