author(s)
Dudipalla Nihanth Kumar and Ashwani Kumar

abstract
The present investigation was conducted to study “Population dynamics and field efficacy of certain insecticides against Whitefly (Bemisia tabaci) (Gen) on Okra” during kharif 2019 at Central Research Field, Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj, Uttar Pradesh (India). The occurence of Whitefly (Bemisia tabaci), commenced from 35th standard week (August fourth week) with an average population of 1.65 (Whiteflies /3 leaves) and then the population increased and gradually reached to its peak level by 42nd standard week (October second week) with an average population of 12.65 (Whiteflies /3 leaves) respectively where after a decline in population was observed as temperature decreased. On the basis of mean percent reduction over control in whitefly population, the treatment of imidacloprid 17.8 SL (81.52%) was found most effective, followed by Fipronil 5% SC (78.50%), Dimethoate 30 EC (74.63%), Malathion 50 EC (72.10%), Azadirachtin 1% EC (69.20%), Buprofezin 25 SC (66.18%), and Spinosad 45 SC (61.83%) was found to be least effective among all insecticides.