Pest
Whitefly
Tiny white flying insects that erupt from leaf undersides when touched
Overview
Whitefly adults are about 1mm long with white waxy wings, resembling tiny white moths. They fly well but not long distances — when disturbed they flutter briefly above the plant before resettling. Nymphs stay fixed on leaf undersides sucking sap and excreting copious honeydew. Whiteflies breed year-round in greenhouse and indoor environments, with short reproductive cycles that allow populations to explode quickly.
Symptoms
Touching the plant sends a cloud of tiny white insects flying from leaf undersides. Leaf undersides show white adults, translucent pale green nymphs, and tiny oblong eggs. Leaves develop chlorotic spots and feel sticky (honeydew). Severe infestations are accompanied by sooty mold. The plant weakens overall with yellowing and leaf drop.
Treatment
Hang multiple yellow sticky traps (2-3 per plant) to catch adults. Apply systemic insecticide (imidacloprid or thiamethoxam) every 5-7 days for 3 treatments, ensuring thorough coverage of leaf undersides. Because adults fly, treat all adjacent plants simultaneously. For extremely dense adult populations, vacuum gently at low speed to remove some before spraying.
Prevention
Use yellow sticky traps as routine monitoring. Regularly inspect leaf undersides, especially of new plants. Maintain good ventilation. Increase monitoring in fall and winter — warm indoor environments allow year-round breeding.
