Effect of insecticides on population of Coccinella septumpuctata Linn, and Chrysoperla carnea Ste. in Cotton field

The results revealed that among the treatments maximum population of C. septumpuctata (LBB) (26.92 adults/5 plant) was recorded in emamectin benzoate 5 WSG @ 8 gai/ha., whereas minimum population (19.92 adults/5 plants) was recorded in cypermefhrin 10 EC @75 gai/ha. Similar trend was observed 5 and 7 DAS where significantly highest populaion 33.63 adults/5 plants, and 29.62 adults/5 plants, respectively were recorded in emamectin benzoate 5 WSG @ 8 gai/ha.. Same trend was observed in C. carnea (GLW) population, the significantly higher population 11.11, 10.61 and 10.43 eggs/30 leaves, recorded 2, 5 and 7 DAS, respectively. This showed that minimum reduction in population of LBB and GLW, over control was found in emamectin benzoate 5 WSG @ 8 gai,/ha. whereas maximum in cypermethrin 10 EC @ gai/ha.. The maximum seed cotton yield (1073.13 kg/ha) recorded in plot treated with emamectin benzoate @ 9.8 gai/ha followed by spinosad 45 SC @ 100 gai/ha and lamada cyhalothrin 5 EC @ 25 gai/ha. It was observed that maximum percentage increase in yield over untreated control (126.4%) and net profit (10338.37 Rs./ha) was recorded in emamectin benzoate @ 9.8 gai/ha treated plots. However, highest cost: benefit ratio 1:17.44 was recorded in plot treated with lamada cyhalothrin 5 EC @ 25 gai/ha.