Residual toxicity of emamectin benzoate and chlorantraniliprole on Eupelmus tachardiae Howard-A key parasitoid of lac insect Kerria lacca (Kerr)

Residual response of emamectin benzoate and chlorantraniliprole against Eupelmus tachardiae Howard (Hymenoptera: Encyrtidae)-a key parasitoid of lac insect, Kerria lacca (Kerr) was assessed under laboratory conditions by exposing the adults on residual film of insecticides. Emamectin benzoate caused 0–14.44% mortality within 1 hr of exposure, 27.5–38.99% mortality within 3 hr, 53.61–96.67% mortality within 18 hr and 100% mortality within 24 hr of exposure except at a very low concentration (0.00025%). Whereas, no mortality with chlorantraniliprole was observed after 1 hr of exposure and within 3 hr of exposure only 3.33 and 8.61% mortality was at 0.0056 and 0.0074% concentration, respectively, which is the recommended dose in lac ecosystem for the management of lepidopteran pests. Within 24 hr of exposure, 30.20–65.31% mortality was observed with concentrations of chlorantraniliprole as against 19.68% in control. Based on mortality within 24 hr of exposure it can be inferred that the emamectin benzoate is relatively more toxic than the chlorantraniliprole. Relatively less toxicity of chlorantraniliprole to this parasitoid species might be attributed due to specificity of this insecticide.