Toxicity of insecticides and biopesticides on mortality and emergence of adultTrichogramma chilonis Ishii. (Hymenoptera: Trichogrammatidae) in greenhouse condition

Abstract

Trichogramma chilonis Ishii. is a common parasitoid on many lepidopteran insect eggs in agricultural ecosystem,but its efficacy can be severely curtailed by pesticide applications. Eight insecticides and two biopesticides were evaluatedto check their compatibility with the Trichogramma parasitoid. Persistent toxicity studies revealed that chlorantraniliprole,Metarhizium rileyi and Beauveria bassiana areshort lived by causing less than 30 per cent mortality at five days oldresidues. Whereas, chlorantraniliprole + lambda-cyhalothrin, emamectin benzoate, spinetoram and imidacloprid were labelledas slightly persistent. Further, thiamethoxam + lambda-cyhalothrin, thiamethoxam and spinosad caused more than 30.00per cent mortality of parasitoids even to the 15 days old insecticide residues and they were classified as moderatelypersistent as per the IOBC classification. Tricho cards tied to the tomato plants sprayed with thiamethoxam + lambda-cyhalothrin, spinetoram and spinosad severely affected the adult emergence of T. chilonis. So, they have to be usedcautiously in the Integrated Pest Management (IPM) programme.