Whiteflies

(Aleyrodinea), a suborder of insects of the order Homoptera. They are usually small insects (1–2 mm) with yellow or reddish bodies and often with dark spots. They have two pairs of almost identical wings which are covered with a white dusty film and which are folded when the insect is at rest, covering the body like a roof. Whiteflies suck the juices of plants and ordinarily remain on the underside of leaves, where they also lay their eggs. The primary larvae are mobile, and the subsequent ones are immobile. There are more than 200 species, with a majority of them found in the tropics. There are approximately 30 species in the USSR. The larvae of the greenhouse, citrus, and strawberry whiteflies are particularly harmful.

The greenhouse, or glasshouse, whitefly (Trialeurodes vaporariorum) is found in hothouses and greenhouses. It damages tomatoes particularly badly, as well as cucumbers and certain flowers. There is a new generation every 25–40 days. The insects heavily infest the leaves of the upper parts of plants, sucking the juices from them. The leaves then turn brown and dry up, and the fruit falls off.

The citrus whitefly (Dialeurodes citri) is found in Japan, India, China, and North and South America; in the USSR it is found on the Black Sea coast of the Caucasus. It is a quarantine pest of citrus fruits. It develops in three or four generations and is spread by the wind and planting stock.

The strawberry whitefly (Aleurodes fragariae) is found in Europe. It damages the cultivated and the common strawberry. The insect develops in three or four generations.

Measures for combating the whitefly include spraying with insecticides and disinfecting hothouses and greenhouses. Parasites—the fungus Aschersonia and the ichneumon fly Encarsia formosa—are used against the citrus whitefly.