Silverleaf Whitefly

Dr. Randy Hudson, Extension Entomologist, The University of Georgia, Department of Entomology, Tifton, GA 31793
Dr. David Adams, Extension Entomologist, The University of Georgia, Department of Entomology, Tifton, GA 31793

Description: The silverleaf whitefly adult is small, isabout 0.9 to 1.2 mm in length, and holds its solid white wings roof-like over a pale-yellow body while at rest. The crawler and nymph look nothing like the adult. The nymphs are flattened, oval scalelike structures. Eggs are oblong and yellow, about 0.2 mm. Hosts: The host range of silverleaf whitefly includes over 500 species of plants. Among these are weeds and cultivated vegetables, agronomic and ornamental crops.

Silverleaf Whitefly Photo by: Philip Roberts, UGA

Damage: Both adult and nymphal silverleaf whiteflies feed on the lower surfaces of leaves by sucking sap with their piercing-sucking mouthparts. Chlorotic spots may appear around feeding sites on the upper surfaces of leaves. Whiteflies produce honeydew upon which sooty mold can grow; thus reducing light penetration; hence, reducing yield and quality. On squash they induce a condition known as silverleaf in which the foliage becomes highly reflective and the fruit is pale in color. On tomatoes silverleaf whitefly can cause a condition known as irregular ripening of the fruit, and they transmit viral diseases.

Life Cycle: The first stage upon hatching is known as the crawler (0.2-0.3 mm) that moves about searching for a suitable site to attach itself on the undersides of the leaf. Once becoming sessile, three more molts occur as a flattened, oval nymph. It requires as little as 18 days to develop from egg to adult under warm temperatures.

Control: On many crops, avoiding insecticide applications is one of the best alternatives economically. However, insecticides tank mixed with piperonyl butoxide or insecticidal soaps give fair to good control. Oil sprays are very helpful in reducing the potential for silverleaf on squash.

In: Roberts, P. M. and G. K. Douce, Coordinators. 1999. Sucking Insects. A County Agent's Guide to Insects Important to Agriculture in Georgia. Univ. of GA, Col. Ag. Env. Sci., Coop. Ext. Serv., Tifton, GA USA. Winter School Top Fifty Agricultural Insect Pests and Their Damage Sessions, Rock Eagle 4-H Ctr., Jan. 20, 1999.

Selected References and Suggested Readings