Field Evaluation of Some Insecticides on some Cowpea Pests and Their Side Effect on Associated Predator (Chrysoperla carnea, steph.).

Abstract

This study was carried out to field evaluate the efficacy of nine insecticides namely chlorpyrifos, emamectin benzoate, thiacloprid, acetamiprid, imidacloprid, indoxacarb, lufenuron, Metahrizum ansoplia, and Kz oil at the recommended rate against aphid, Aphis craccivora Koch; whitefly, Bemisia tabaci (Genn.); the green bug, Nizara viridula L; the cotton leafworm, Spodoptera littoralis (Boisd.) and its predator Green lacewing, C. carnea (Stephens) under field conditions during 2013 and 2014 Cowpea seasons. Data showed that emamectin benzoate and chlorpyrifos were the highest effect in initial kill, residual effect and mean reduction on A. craccivora, B. tabaci, N. viridula and S. littoralis; while Kz oil and Metahrizum ansoplia were the lowest effect, during 2013 and 2014 seasons.Imidacloprid, thiacloprid and acetamiprid recorded moderate effect in initial kill, residual effect and mean reduction on B. tabaci and N. viridula while they recorded low effect on S. littoralis. Indoxacarb caused the moderate effect against S. littoralis while it recorded low effect on B. tabaci.On the other hand lufenuron showed high effect on A. craccivora and S. littoralis andrecorded moderate effect on the N. viridula; while it recorded low effect on B. tabaci.The most toxic insecticides to C. carnea were chlorpyrifos, lufenuron and emamectin benzoate while Kz oil and Metahrizum ansoplia were toxic less to the predator on the studied two seasons.