Toxicity and Sublethal Effects of Lambda-Cyhalothrin Insecticide on Parent and Filial Generations of (Coleoptera: Coccinellidae).

Lambda-cyhalothrin is a synthetic pyrethroid insecticide that is widely used to control leaf-eating pests. Because of increased insecticide resistance, an understanding of sublethal cross-generational effects of insecticides is important. We examine the effects of sublethal concentrations (SLCs) (LC, LC, and LC) of lambda-cyhalothrin on the growth, reproduction, and detoxification enzyme activities of F and F generation . Lambda-cyhalothrin is toxic to adult , with an LC at 48 h of 0.355 mg L. At SLCs, lambda-cyhalothrin significantly reduces the longevity and average fecundity of F and F adults, and prolongs the durations of the egg, larval, and pupal stages and adult preoviposition period. Additionally, an increased lambda-cyhalothrin concentration significantly decreases net reproductive rates, and both finite and intrinsic rates of increase in the F generation, and significantly increases the average generation cycle. The detoxification enzyme activity of F adults treated with SLCs of lambda-cyhalothrin for 48 h trends upwards. Results indicate that low concentrations of lambda-cyhalothrin induce glutathione S-transferase and carboxylesterase activities and inhibit multifunctional oxidase activity. The growth, development, and reproduction of the F population remain inhibited by lambda-cyhalothrin treatment in the adult stage, and inhibitory effects increase with increased lambda-cyhalothrin concentration. The control efficacy of lambda-cyhalothrin against shows cross-generational effects.