Diversity of major predators under different insecticide regimes in two important growth stages of rice

The effect of twelve different groups of insecticides on diversity of major predators (insects and spiders) during active tillering and bootleaf stage of rice crop was evaluated in West Bengal. The results showed that spinosad, emamectin benzoate, sulfoxaflor and pymetrozine were highly safe while buprofezin, imidacloprid, indoxacarb and chlorantraniliprole were moderately so. The insecticides like lambdacyhalothrin, fipronil and chlorpyriphos were found to be toxic. During active tillering stages the predator diversity was maximum in emamectin benzoate treatment and least in case of lambdacyhalothrin. Similar trend was observed for evenness index in the emamectin benzoate and lambdacyhalothrin. During boot leaf stage, Shannon index was maximum in sulfoxaflor and minimum in lambdacyhalothrin. Overall, insecticidal treatments resulted in decrease in diversity of predators during both stages of rice crop.