Scott Bauer, USDA Agricultural Research Service, Bugwood.org
Whiteflies
The whiteflies, comprising only the family Aleyrodidae, are small hemipterans. More than 1550 species have been described. (shown silverleaf whitefly)
Whiteflies typically feed on the underside of plant leaves. Feeding damage can cause economic losses, it is the ability of whiteflies to transmit or spread viruses that has had the widest impact on global food production.
Whiteflies feed by tapping into the phloem of plants, exposing plants to the whiteflies' toxic saliva and decreasing the plant's overall turgor pressure. The damage is quickly elevated as whiteflies congregate in large numbers, quickly overwhelming susceptible plants. Damage is further exacerbated as whiteflies, like aphids, excrete honeydew as a waste product, which promotes mold growth and may seriously impede the ability of farms to process cotton harvests.
Whiteflies share modified form of hemimetabolous metamorphosis, in that the immature stages begin life as mobile individuals, but soon attach to a host plant. The stage before the adult is called a pupa, though it shares little in common with the pupal stage of holometabolous insects. The video to the right which shows a severe infestation can be enlarged for better viewing.
