Side effects of azadirachtin on some important beneficial insects in laboratory

Abstract

The toxic effect of azadirachtin (0.3 g/L) in recommended dose, its half and twice doses were tested on Encarsia formosa, Aphidius colemani, Orius laevigatus and Nesidiocoris tenuis under laboratory conditions. The mortalities of nymphs and adults were evaluated by the IOBC toxicity rating scale for pesticides. As a result of the study, the product was harmful to O. laevigatus and N. tenuis adults and E. formosa pupa. Slightly and moderately harmful on N. tenuis nymph and A. colemani at recommended and twice doses. In recommended dose it was harmless only on N.tenuis male and E. formosa pupa at 24 h. Twice dose of the product was very toxic to all of the beneficial insects. The adulticide effects on males and females of O. laevigatus and N. tenuis in half dose at 48 h were found to be 83.33% and 75.00% and 78.26% and 76.20%, respectively. Additionally, little toxic effect (28%) was detected for A. colemani at half dose after 48 h. Similarly, at this dose, the mortality rates indicated less toxic effects on N. tenuis nymphs. In conclusion, it was understood that the recommended and twice doses of azadirachtin had negative effects on natural enemies. It was suggested that azadirachtin should be used carefully in pest control programs.