Vertical Distribution and Abundance of Aleyrodids of Agricultural Importance In Himachal Pradesh

Surveys conducted in different locations under open field conditions and protected environment representing different agroecological zones of Himachal Pradesh revealed four aleyrodids viz., Aleurocanthus sp., Bemisia tabaci (Gennadius), Dialeurodes citri Ashmead and Trialeurodes vaporariorum(Westwood) as associated with herbaceous and fruit crops. Aleurocanthus sp. and B. tabaci were prevalent in the submountainous and low-hill subtropical zone (Zone I). Incidence of Aleurocanthus sp. was observed only during summer, abundance being low and associated with host plants belonging to the family Rutaceae. Whereas, B. tabaci was observed under both open as well as protected environment infesting ten host plants belonging to five families. Dialeurodes citri was associated with host plants belonging to the family Rutaceae and was distributed in Zone I and II (mid hills sub- humid zone). It remained active in Zone I throughout year except in winter, whereas, in Zone II it was found active during south-west monsoon and post-monsoon season only. Trialeurodes vaporariorum was prevalent in Zone II and high-hills temperate wet zone (Zone III) infesting 49 host plants belonging to 23 families under open field conditions and protected structures, respectively. It remained active throughout year in Zone II surviving through winter season on Canadian horseweed Erigeron canadensis (L.) Cronquist under open field conditions. Under protected environment T. vaporariorum remained active throughout year in Zone II and was prevalent only during summer in Zone III. High hills temperate dry zone (Zone IV) (>2501 masl) remained free of aleyrodid infestation.