Abstract:

Objective To investigate the levels of resistance and the resistance stability of Blattella germanica to five commonly used insecticides, i.e., beta-cypermethrin, chlorpyrifos, acephate, propoxur, and deltamethrin, in Fengtai district, Beijing, China.Methods The B. germanica used in this study was the first filial generation (F1 generation) and that was bred in the laboratory followed by one-year normal feeding. The insecticide film method recommended by the World Health Organization was used to determine the median knock-down time (KT₅₀) and the corresponding 95% confidence interval (95%CI), knock-down rate, and mortality rate of B. germanica exposed to the five commonly used insecticides and to assess the levels of resistance and the resistance abatement of B. germanica. Results The mean coefficients of resistance (R/S) of the F1 generation of B. germanica to beta-cypermethrin, acephate, deltamethrin, propoxur, and chlorpyrifos were 7.91, 1.90, 30.52, 4.56, and 2.06, respectively. The rates of resistance decline in B. germanica after one-year exposure to the five commonly used insecticides were 42.82%, 49.70%, 74.77%, 56.51%, and -24.19%, respectively. Conclusion Blattella germanica has developed different levels of resistance to the five commonly used insecticides in Fengtai district, Beijing. After feeding for one year in the laboratory, the rates of resistance of B. germanica declined for more than 40% for all insecticides except chlorpyrifos.

Key words: Blattella germanica, Insecticide resistance, Resistance abatement

摘要：

目的 了解北京市丰台区德国小蠊对高效氯氰菊酯、乙酰甲胺磷、溴氰菊酯、残杀威、毒死蜱的抗药性及其抗性衰退情况。方法 采用WHO推荐的药膜法,测定经实验室饲养1代和正常饲养1年后的试虫对常用杀虫剂的半数击倒时间(KT₅₀)及其95%置信区间(95%CI)、击倒率、死亡率,评价其抗药性程度及抗性衰退情况。结果 德国小蠊现场种群对高效氯氰菊酯、乙酰甲胺磷、溴氰菊酯、残杀威和毒死蜱的抗性倍数分别为7.91、1.90、30.52、4.56和2.06倍;饲养1年后,其抗性消退率分别为42.82%、49.70%、74.77%、56.51%和-24.19%。结论 丰台区德国小蠊现场种群对5种常用杀虫剂均产生不同程度的抗性;饲养1年后,除毒死蜱外,对其他杀虫剂的抗性均有所消退,抗性消退率均达40%以上。

关键词: 德国小蠊, 抗药性, 抗性消退