Whitefly (Silverleaf Whitefly)

📖 Description

Silverleaf Whitefly (Bemisia tabaci) is one of the most destructive agricultural pests worldwide and the single most important vector of plant viruses in the Indian subcontinent, attacking over 500 plant species including cotton, tomato, chilli, brinjal, okra, cucurbits, cassava, tobacco and soybean. The pest transmits more than 100 plant viruses — including Cotton Leaf Curl Virus (CLCuV), Tomato Leaf Curl Virus (ToLCV), Chili Leaf Curl Virus, Mungbean Yellow Mosaic Virus and Cassava Mosaic Virus — that cause annual losses exceeding ₹20,000 crore in Indian agriculture. Cotton Leaf Curl Virus alone has caused annual losses of over ₹3,000 crore in Punjab, Haryana and Rajasthan cotton belts since the 1990s. The pest is particularly problematic because (a) it has a very wide host range making rotation difficult, (b) it has developed resistance to virtually all major insecticide classes, (c) the B biotype (also called Middle East-Asia Minor 1, MEAM1) is an especially aggressive invasive strain that has displaced native biotypes worldwide, (d) it reproduces rapidly (15-20 generations per year in tropical India) and (e) it feeds on leaf undersides where contact insecticides don’t reach. IPM with yellow sticky trap monitoring, biological control (Encarsia formosa parasitoid, Amblyseius swirskii predatory mite, Verticillium lecanii fungus), neem-based sprays, and need-based insecticide rotation provides effective and sustainable control. The pest is most severe in continuous cropping of susceptible hosts and in areas where weed hosts serve as reservoirs between cropping cycles. Climate change is expanding the range of the whitefly into previously cooler crop-growing regions, making the pest an increasing concern.