Laboratory expennients were conducted to determine the efficiency of different pesticides belonging to various biological and synthetic chemical groups against 2d instar larvae of cotton leefworm Si?tor&is ( Boisd) and Aphis gossypii (Glover). Results revealed that LC50 and toxicity index of the tested compounds against 2d instar taivae of cotton leafworrn were (1.544.17 and 10.55 ppm) and ( 100, 36.88 and 14.56 % ) for Betacyfolathrin, Fenpropethon and EsFenvolerate, respectively. Although for the Bío-cornpounds, Spinosad and Abamactin the obtained values of the two tested compounds were 21.40 and 150.88 ppm )and(lOCand 14.18 % ) respectively. In case of Aphids pest values of LC50 and toxicity index were (0.015, 0.026, 0.042, 0.171, 0.29 and 0.503 ppm) and (1001 57.69, 35.71, 877, 5.17 and 2.98 %), for Beta-Cyofiathrin, Es-Fenvolerat, Chioropyrilos, Profenfos, Fenpropathrin, and Methomyl, respectively, while ¡t were (17.51 2, 68.522 and 0.156 ppm ) and (100, 0.89, and 0.23) for Beeuvena basaana ,Abamectin and Spinosad biocides, respectively. Co-toxicity factors of the binary mixture of ( Beta-Cfoluthnn + Abamectin) and ( Beta- Cyfoluthrin • Spinosad) at LCs levels against 2 instar larvae of cotton iealworn and A.gossypì were ( - 28.57 and 100 ) and ( - 3714 and 72.97 ) respectively.