The greenhouse whitefly (Trialeurodes vaporariorum) is a typical pest that affects greenhouse and open field crops.
Greenhouse whitefly larvae and adults suck plant juices. Secretion of honeydew fouls the leaves and the fruits, which then become non-marketable. Often mould grows on the honeydew, which retards photosynthesis and respiration of the plant.
Adult greenhouse whiteflies measure about 2 mm and are covered with a white waxy powder. Their wings are positioned horizontally and overlap slightly. The female greenhouse whitefly deposits its oval-shaped eggs of 0.2 mm on the underside of leaves at the top of the plant. After 2 - 3 days they turn black. The larva that hatches is mobile for a few hours during which time it searches for a suitable place on the leaf to settle. Later on, and in the subsequent larval and pupal stages, it does not move anymore. Its four larval stages look very similar, but differ clearly in size. The white, transparent pupa is round with an upright edge and is covered with hairs. An adult greenhouse whitefly emerges from the pupa through a T-shaped exit hole. On tomato, development from egg to adult takes 20 days at 27°C or 38 days at 17°C, but on other host plants this can be quite different. Also fertility depends on temperature and host plant. A female lays about 100 eggs on tomato, 200 eggs on cucumber and 300 eggs on eggplant.