2013年,采用田间调查和室内浸叶法研究了云南通海县菜区小菜蛾种群消长特点及其对9种杀虫剂的抗药性。结果表明,通海小菜蛾田间种群全年发生,呈现3~4个峰期。2月份后种群数量逐渐增加,10月份后逐渐下降。高峰期成虫虫量单盆可达69.9头/d,幼虫1.72头/株。与敏感种群比较,通海县小菜蛾种群对丁醚脲和苏云金芽孢杆菌的抗性指数分别为1.63和2.85,为低抗水平;对茚虫威的抗性指数为20.7,为中等水平抗性;对溴虫腈、氯虫苯甲酰胺、多杀菌素和啶虫隆的抗性指数分别为42.18、43.04、43.9和55.17,为高水平抗性;对高效氯氰菊酯和阿维菌素的抗性指数分别为345.35和837.9,为极高水平抗性。通海小菜蛾田间种群对9种杀虫剂的抗性指数大小顺序为:高效氯氰菊酯>阿维菌素>啶虫隆>多杀菌素>氯虫苯甲酰胺>溴虫腈>茚虫威>苏云金芽孢杆菌>丁醚脲。 In 2013, the population dynamics of diamondback moth (Plutella xylostella) and its resistance to nine insecticides in Tonghai County of Yunnan Province were studied by field investigation and indoor dipping leaf method. The results showed that the field population of the diamondback moth, Plutella xylostella, occurred throughout the year with 3-4 peak periods. After February, the population gradually increased and gradually decreased after October. The peak adult worm population single basin up to 69.9 head / d, larva 1.72 / plant. Compared with the susceptible population, the resistance index of diafenthiuron and Bacillus thuringiensis to diamondback moth in Tonghai County was 1.63 and 2.85, respectively, which were low resistant level. The resistance index to indoxacarb was 20.7, which was moderately resistant. The resistance index to chlorfenapyr, chlorantraniliprole, spinosad and niceronide were 42.18, 43.04, 43.9 and 55.17, respectively, which were high level of resistance. The resistance index to cypermethrin and abamectin 345.35 and 837.9 respectively, for a very high level of resistance. The order of the resistance index of the nine populations of the diamondback moth, Plutella xylostella, to the nine insecticides was as follows: beta-cypermethrin> abamectin> pyridinecarbamycin> spinosad> chlorantraniliprole> chlorfenapyr> indoxacarb> Bacillus> Diafenthiuron.