whitefly

Whitefly refers to a group of small, sap-sucking insects in the family Aleyrodidae, order Hemiptera. The most significant agricultural species are Bemisia tabaci (the whitefly complex, including the greenhouse and sweet potato forms) and Trialeurodes vaporariorum (the greenhouse whitefly). Whiteflies occur worldwide, especially in warm climates and in greenhouses. Adults are typically 1–2 mm long, with white wings held rooflike over the body; immatures (nymphs) are on the undersides of leaves and are more scale-like.

Life cycle and identification are simple to observe: females lay eggs on leaf surfaces, often near veins; eggs hatch into mobile crawlers that move a short distance before settling as wingless nymphs. Nymphs molt through several instars before becoming winged adults. Development from egg to adult depends on temperature and can yield multiple generations per year under favorable conditions, enabling rapid population growth.

Damage from whiteflies includes direct feeding, which can cause chlorosis, leaf curling, and stunted growth. They also excrete honeydew, which promotes sooty mold on foliage and reduces photosynthesis. In addition, whiteflies are vectors for plant viruses, particularly begomoviruses and other pathogens, contributing to significant crop losses.

Management generally relies on integrated pest management. Monitoring with yellow sticky traps helps detection and population assessment. Cultural controls include removing heavily infested leaves and weed management. Biological control with parasitoids such as Encarsia formosa and Eretmocerus species, along with predatory insects, can reduce populations. Chemical controls are challenging due to the waxy covering and resistance, so they are typically used selectively and rotated to minimize resistance.