whitefly

/hwuyt"fluy', wuyt"-/, n., pl. whiteflies.

any of several plant-sucking, homopterous insects of the family Aleyrodidae, having the body and wings dusted with a white, powdery wax, and being widely distributed chiefly in tropical regions where they are often serious crop pests, as Dialeurodes citri (citrus whitefly), commonly occurring on citrus trees, and Trialeurodes vaporariorum (greenhouse whitefly), inhabiting greenhouses.

[1885-90; WHITE + FLY²]

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Any sap-sucking member of the insect family Aleyrodidae (order Homoptera).

Nymphs are flat, oval, and usually covered with a cottony substance. Adults, 0.08–0.12 in. (2–3 mm) long, are covered with a white opaque powder and resemble moths. Whiteflies are abundant in warm climates, on houseplants, and in greenhouses. The greenhouse whitefly is one of the most abundant and destructive members of the family. The citrus whitefly and citrus blackfly damage fruit and other crops by sucking sap and producing honeydew, a by-product of digestion on which grows a sooty fungus that ruins fruit and reduces the host plant's ability to photosynthesize.

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▪ insect

 any sap-sucking member of the insect family Aleyrodidae (order Homoptera). The nymphs, resembling scale insects, are flat, oval, and usually covered with a cottony substance; the adults, 2–3 mm (0.08–0.12 inch) long, are covered with a white opaque powder and resemble tiny moths. The four wings develop within the insect and evert during the last molt. These pests are abundant in warm climates and are found on houseplants and in greenhouses.

      The citrus whitefly (Dialeurodes citri) is economically important, sucking sap from orange and date trees and producing honeydew, a sweet by-product of digestion, upon which a sooty fungus grows that ruins the fruit. Control is by oil or parathion sprays.

      The citrus blackfly (Aleurocanthus woglumi) is well-established in Mexico and the West Indies. A sooty fungus that grows on the honeydew excreted by the citrus blackfly reduces the host plant's ability to photosynthesize.

      The greenhouse whitefly (Trialeurodes vaporariorum) is one of the most abundant and destructive members of the family. It damages plants by reducing vigour and causing them to wilt, turn yellow, and die. Sprays that kill both adult and larval stages are necessary to control this pest.

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