Comparative effectiveness of insecticides against Bemisia tabaci (Gennadius) on bt cotton from Punjab under laboratory conditions

The study evaluated the effectiveness of various insecticides on whitefly populations from Fazilka, Mansa and Ludhiana in Punjab during kharif 2023 crop season. After 24 h, diafenthiuron 50 WP and dinotefuran 20 SG achieved 100% mortality, except in Ludhiana, where only diafenthiuron was effective. Mansa population did not achieve 100% mortality at 24 h. After 48 h, ethion and pyrifluquinazon 20 WG (494 and 371 g ha^-1) in Fazilka and pyrifluquinazon 20 WG (494 g ha^-1) and afidopyropen 50 DC in Ludhiana achieved 100% mortality. Mansa again did not achieve 100% mortality. After 72 h, afidopyropen 50 DC and clothianidin 50 WDG in Fazilka and ethion, clothianidin 50 WG in Ludhiana achieved 100% mortality. In Mansa, 100% mortality was achieved with afidopyropen 50 DC, ethion, diafenthiuron, pyriproxyfen and pyrifluquinazon (494 and 371 g ha^-1). The lowest lethal time was recorded with pyrifluquinazon in Fazilka (6.3 h), Ludhiana (6.1 h) and Mansa (14.6 h).