Observations on comparative efficacy of insecticides against Carcella illota and Bacillus thuringiensis

Abstract

A recent study was carried out to determine the relative toxicity of nine commonly used insecticides viz. cypermethrin 25%EC, endosulfan 35% EC, carbaryl 5%DP, cyhalothrin 5% EC, phosalone 35%EC, deltamethrin 2.8%EC, monocrotophos 36%SL, thiodicarb 75%WP, and chlorpyriphos 50%EC, to the natural enemies Carcella illota and Bacillus thuringiensis, under the laboratory conditions. Insecticides were tested at field recommended dose according to the standard method for testing side effects of insecticides on natural enemies of insect pests. In the laboratory initial toxicity test phosalone, thiodicarb and endosulfan were found to be harmless to Carcella illota and Bacillus thuringiensis. Cypermethrin and monocrotophos were slightly harmful to Carcella illota but harmless to Bacillus thuringiensis. The results obtained in the present study showed that all the nine insecticides were not equally effective to both the bio-agents. Carbaryl and cyhalothrin were found to be most toxic to both the natural enemies.