Monitoring the Resistance of the Beet Armyworm (Lepidoptera: Noctuidae) to Four Insecticides in Southern China from 2014 to 2018

Abstract The beet armyworm Spodoptera exigua (Hübner) is a serious polyphagous pest that infests vegetable crops worldwide and has rapidly developed resistance due to its long-term exposure insecticides. current statuses four insecticides exhibited by three field populations of armyworms collected in southern China from 2014 2018 were investigated. Monitoring data five consecutive years demonstrated all tested S. extremely high chlorantraniliprole (220.58- 2,597.39-fold). Two (Baiyun Fengxian) low moderate spinosad, whereas the Huangpi population remained susceptible (except 2014, with RR 6.11-fold). Fengxian Baiyun indoxacarb steadily increased over years, relatively slowly. methoxyfenozide, susceptibility (1.06- 6.45-fold) (1.53- 14.22-fold) methoxyfenozide. These results suggest should not be employed control this China. Reduced use methoxyfenozide or alternating levels recommended. Spinosad remains an effective insecticide for management exigua. To avoid rapid development resistance, rotations different modes action based on patterns performed