Abstract:The susceptibilities of eggs, 2nd, 3rd, 4th instar larvae and adults and antifeedant effect of Spodoptera exigua to chlorantraniliprole and flubendiamide were investigated using egg-dip method, leaf-dip method, topical application, stomach poison test, residual film and fed poison nutrient solution method. The results indicate that there were no ovicidal activities in the two insecticides, but the survival rates of neonate larvae were decreased with the concentration of the two insecticides increased. The toxicity of two insecticides to 2nd instar larvae was the highest, which were 1.50-, 6.17-fold than the 3rd instar larvae and 22.25-, 44.95-fold than 4th instar larvae. Two insecticides had good oral toxicity to 4th instar larvae of S.exigua, and were 14.10-, 8.44-fold than the contact toxicity, respectively. The activities of the two insecticides to adults indicated that the chlorantraniliprole was higher than flubendiamide with the toxicity ratios were 25.53 to 34.19-fold. The results of antifeedant test showed obvious antifeedant effect to larvae of S.exigua after treatment with the two insecticides. After 48 h, antifeedant ratio reached the maximum, and the ratios were 82.73%, 84.15%. The larvae showed feeding cessation, lethargy and muscle paralysis after treated with two insecticides.