The Greenhouse Whitefly (Trialeurodes vaporariorum) was first observed in tomatoes in America in 1870 and is a major pest in a wide variety of vegetable and ornamental crops around the world.

Greenhouse Whitefly adults are 1.5mm long and have a distinctive white appearance.

The adults tend to lay their eggs onto the soft young plant growth at the top of the plant. Eggs are white and turn black prior to hatching. The whitefly larva is mobile for about a day and then attaches itself to the leaf surface, where it feeds from the plant until it moults into a pupae. During this attached stage, the whitefly is called “scale” because of its scale-like appearance and behaviour. An adult hatches from the pupae and the Greenhouse Whitefly lifecycle repeats.

The two most important factors affecting whitefly population growth are temperatures and the plant host. Greenhouse Whiteflies will continue to breed throughout the year in temperate climates. The whitefly eggs can survive more than 15 days at –3°C and the number of eggs laid by a single female varies greatly depending on the plant species and even varieties of plants within a species.

Greenhouse Whiteflies can be found in conjunction with the Silverleaf Whitefly (Bemisia tabaci).