BEPLS Vol 7 [4] March 2018 10 | P a g e ©2018 AELS, INDIA Bulletin of Environment, Pharmacology and Life Sciences Bull. Env. Pharmacol. Life Sci., Vol 7 [4] March 2018 :10-14 ©2018 Academy for Environment and Life Sciences, India Online ISSN 2277-1808 Journal’s URL:http://www.bepls.com CODEN: BEPLAD Global Impact Factor 0.876 Universal Impact Factor 0.9804 NAAS Rating 4.95 ORIGINAL ARTICLE OPEN ACCESS Bio-Efficacy of Different Insecticides against Thrips (Scritothrips dorsalis Hood) and Whitefly (Bemisia tabaci Gennadius) on BT Cotton P. V. Patil, V. K. Bhamare And P. P. Pate Department of Agricultural Entomology, College of Agriculture, Latur-413 512 (MS), Vasantrao Naik Marathwada Krishi Vidyapeeth, Parbhani ABSTRACT Field evaluation of new insecticidal molecules i.e. neonicotinoids was conducted against thrips and whiteflies on Bt cotton. The new molecules tested were imidacloprid 17.8 SL 0.004 per cent, acetamiprid 20 SP 0.002 per cent, 25 per cent WG 0.005 per cent, clothianidin 50 WDG 0.01 per cent, fipronil 5 SC 0.015 per cent, diafenthiuron 50 WP 0.060 per cent, dimethoate 30 EC 0.04 per cent. Fipronil recorded significant superior in reducing thrips population which was on par with diafenthiuron followed by other insecticides up to 14 days after first and second spray. Fipronil recorded the lowest number of whiteflies in cotton ecosystem followed by acetamiprid and other treatments up to 14 days after third spray. Keywords: Scritothrips dorsalis Hood, Bemisia tabaci Gennadius, BT COTTON Received 20.11.2017 Revised 17.12.2017 Accepted 13.02.2018 INTRODUCTION Cotton is most important commercial crop known as “king of natural fiber” and world over commonly referred as “white gold” which belongs to family Malvaceae and genus Gossypium. Cotton plays an important role in strengthening economy of 82 countries across the world [1-5]. Cotton was cultivated in about 35.7 M hectares area across the world and in about 12.2 M hectares area in India. During 2014-15, the total cotton production in India was 400.00 lakh bales of 170 kg/bale with average productivity of 537 kg/ha [6]. In Maharashtra cotton was grown in about 41.92 lakh ha area with the production of 85 lakh bales of 170 kg/bale and average productivity of 345 kg/ha during 2014-15 [6]. At national level Maharashtra ranked first in area, second in production and eleventh in productivity [6]. Introduction of Bt cotton technology solved the bollworm problem but continuous cultivation of Bt cotton has at some places led to increased incidence of sucking and other pests in the recent years [7]. The important sucking insect-pests attacking Bt cotton are jassid (Amrasca biguttula biguttula Ishida), thrips (Scirtothrips dorsalis Hood), aphid (Aphis gossypii Glover.), whitefly (Bemisia tabaci Gennadius) and mealy bug (Phenacoccus solenopsis Tinsley). Among that thrips nymph and adults lacerating the leaf and cause damage to seedling and seedling becomes wrinkled and distorted with white shiny patches; infected older crop presents rusty appearance in the field. Nymphs and adults of whiteflies by sucking cell sap causes upward curling of leaves reduce plant vigour, lint contamination with honey dew and associated fungi and also transmit leaf curl virus disease. Several new groups of insecticides have been recommended against sucking pest complex of cotton. But according to several reports many recommended label claimed insecticides could not ascertain effective results. Hence these label claimed insecticides at existing recommended doses should have to be reevaluated against sucking pest complex of cotton for effective management. MATERIALS AND METHODS The field experiment with cotton crop using variety RCH-2 (BG-II) in Kharif 2014 was conducted at the Research Farm of Department of Agricultural Entomology, college of Agriculture, Latur (Vasantrao