Insecticides causing resurgence in brown plant hopper, Nilaparvata lugens in irrigated rice
A field trial was conducted at Regional Agricultural Research Station, Warangal, Telangana State for three consecutive Kharif seasons of 2010, 2011 and 2012 to study the resurgence effect of certain insecticides against brown plant hopper, and effect on mirid bug and spiders. The results clearly indicated that buprofezin 25 SC @ 1.6 ml/l recorded the lowest brown plant hopper and highest predator population at 5 and 10 days after first and second sprayings, whereas, lambdacyhalothrin 2.5 EC @ 1 ml/l and chloripyriphos 20 EC @ 2.0 ml/l increased the population of hoppers and decreased population of predators at 5 and 10 days after second spray and were more than the untreated control. Buprofezin 25 SC @ 1.6ml/l recorded significantly highest yield (5960 kg/ha) and higher benefit: cost ratio (1.8).