The greenhouse whitefly (Trialeurodes vaporariorum) is a widespread and economically significant pest that primarily affects vegetable and ornamental crops grown in greenhouses. Originally native to tropical and subtropical regions of the Americas—likely Brazil or Mexico—this pest has since become established across the globe. The greenhouse whitefly has an extensive host range, feeding on hundreds of plant species from a wide variety of families. Commonly affected crops include aubergine, beans, cucumber, sweet pepper, tomato, roses, gerbera, and poinsettia. Its ability to reproduce rapidly and infest diverse plant types makes it a persistent challenge for both commercial growers and hobbyists.

Damage Symptoms:

Whiteflies cause damage primarily through their feeding behavior and the secretion of honeydew. The larvae require large amounts of protein for development, prompting them to consume significant quantities of plant sap, which is high in sugar. This excess sugar is expelled as honeydew, especially in large quantities by older larvae. The act of sap-sucking weakens the plant and disrupts its physiological processes. In high populations, this feeding can cause stunted growth, leaf wilting, and defoliation—particularly under strong sunlight. These effects can significantly hinder fruit development and reduce overall yield.

The honeydew itself contributes to secondary damage. It creates a sticky surface on fruit and leaves, attracting dirt and encouraging the growth of sooty moulds (Cladosporium spp.). This black mould not only diminishes the aesthetic value of ornamental plants but also interferes with photosynthesis and transpiration, further weakening the plant. In severe infestations, affected fruit can rot, rendering it unsellable. Moreover, whiteflies are vectors for various plant viruses, adding to their economic and visual impact in both food and ornamental crops.