The toxicological effects of some insecticide mixtures (chlorpyrifos, pyridalyl, chlorantraniliprole, emamectin benzoate, and methoxyfenozide), against the 3 rd instar of Spodoptera larvae were evaluated. The results indicated that, LC 50 values for each insecticide were 12.44, 0.88, 0.08, 0.16 and 3.35 mg L-1 respectively, and 0.458, 0.009, 0.0014 and 0.357 mg L-1 respectively.Also, the LC 50 values of chlorpyrifos are increased by larvae weight increased. LC 50 values of chlorpyrifos as a function of postfeeding initiation of Spodoptera larvae to pyridalyl, chlorantraniliprole, emamectin benzoate, and methoxyfenozide after two days (single exposure) were 1.33, 1.99, 0.74, and 0.37 mg L-1 respectively. Therefore, post-feeding initiation of larvae to previous insecticides tremendously decreased LC 50 values of chlorpyrifos.Also, the percent inhibition of AChE from Spodoptera head capsules by chlorpyrifos, pyridalyl, chlorantraniliprole, emamectin benzoate, and methoxyfenozide (LC 10 equivalent concentrations) were 44.5, 23.4, 19.4, 33.5, and 15.4%, respectively. The percent inhibition of AChE from Spodoptera head capsules by chlorpyrifos either pre-treatment or post-treatment with pyridalyl, chlorantraniliprole, emamectin benzoate, and methoxyfenozide were increased. This indicates that the toxic potential of these pesticides for the tested organism is greater when present in a mixture than in an individual.