1Institute of Vegetables，Wuhan Academy of Agricultural Sciences，Wuhan 430345，Hubei，China；2College of Plant Science and Technology，Huazhong Agricultural University，Wuhan 430070，Hubei，China
Abstract：On the basis of establishing the baseline of susceptibility of Spodoptera exigua（Hübner）to 11 insecticides，the resistance levels of 4 field populations to 11 insecticides were detected by leaf-dipping method，and the control efficacy of 8 insecticides against S. exigua were evaluated in field trails．The results showed that the 4 tested S. exigua populations remained susceptible to spinosad and methomyl，while developed varying degrees of resistance to other tested insecticides as follows：low to moderate resistance to methoxyfenozide，chlorfenapyr and indoxacarb，moderate resistance to chlorpyrifos，moderate to high resistance to chlorfluazuron，chlorantraniliprole and tolfenpyrad，and high resistance to emamectin benzoate and beta-cypermethrin．The results of the field efficacy showed that the control efficacy of chlorfenapyr 10% SC against S. exigua ranging from 73.62% to 92.97%，and the highest control efficacy appeared on the third day after treatment．The following were chlorfluazuron 50 g · L-1 EC，methoxyfenozide 24% SC and indoxacarb 150 g · L-1 SC，all with the highest control efficacy exceeding 80%．The highest control efficacy of tolfenpyrad 15% SC and chlorantraniliprole 5% SC were 71.70% and 70.55% respectively．The control efficacy of beta-cypermethrin 4.5% EC and emamectin benzoate 5.7% ME had the lowest control effect，with the maximum control efficacy less than 50%．
