Abstract: Objective To investigate the resistance of Musca domestica to six hygienic insecticides in Jinnan district, Tianjin, China, to explore the pattern of changes in the resistance of M. domestica to insecticides in Jinnan district by comparing that to the results monitored in 2014 and taking into account the history of use of insecticides in Jinnan district, and to provide a scientific basis for the prevention and control of M. domestica. Methods In August, 2017, M. domestica was collected from agricultural markets, livestock farms, and dump sites in Jinnan district, Tianjin. The micro-titration method was used to determine the resistance of M. domestica to insecticides. The laboratory results were statistically analyzed using DPS 7.05; a regression curve for virulence, median lethal dose (LD₅₀), and 95% confidence interval (CI) were calculated. Results The resistance of M. domestica to six insecticides was observed in Jinnan district, with an upward trend in the resistance found in four comparable insecticides (propoxur, beta-cypermethrin, permethrin, and deltamethrin) as mentioned above. The resistance to propoxur was highest with a LD₅₀ of >15 μg/♀ and a resistance ratio of >352.94. The LD₅₀ for beta-cypermethrin, permethrin, deltamethrin, lambda-cyhalothrin, and pirimiphos-methyl was 0.054 8, 0.108 0, 0.095 1, 0.064 3, and 0.743 6 μg/♀, respectively, with the corresponding resistance ratios as 91.33, 9.64, 158.50, 20.09, and 11.05, compared with the susceptible strains reported in the literature. Compared with the results monitored in 2014, the resistance levels were on the rise, with the resistance ratios to propoxur, beta-cypermethrin, permethrin, and deltamethrin as >12.60, 14.81, 9.15, and 3.37, respectively. Conclusion Musca domestica in Jinnan district have developed a resistance to various insecticides with a rising trend in resistance. Sustainable prevention and control strategies aiming at environmental and physical control are recommended. It is advisable to choose low-resistance chemical insecticides based on the insecticide resistance monitoring results, and to avoid using the same insecticide against M. domestica for a long period of time.

Key words: Musca domestica, Micro-titration method, Insecticide, Insecticide resistance

摘要： 目的 调查天津市津南区家蝇对6种卫生杀虫剂的抗药性水平，并与2014年监测结果进行比较，结合津南区蝇类用药史，探索津南区家蝇抗药性变迁规律，为科学防控提供依据。方法 2017年8月在天津市津南区的农贸市场、牲畜养殖场和垃圾集散处等地采集家蝇；采用微量点滴法测定其抗药性。实验室结果所得数据采用DPS 7.05软件进行统计学分析，计算毒力回归线、半数致死量（LD₅₀）及其95%可信区间。结果 津南区家蝇对6种药剂均产生了抗药性，其中可比较的4种药剂（残杀威、高效氯氰菊酯、氯菊酯和溴氰菊酯）抗性有上升趋势。对残杀威抗性水平最高，LD₅₀>15 μg/♀，抗性倍数>352.94倍；对高效氯氰菊酯、氯菊酯、溴氰菊酯、高效氯氟氰菊酯、甲基嘧啶磷LD₅₀值分别为0.054 8、0.108 0、0.095 1、0.064 3和0.743 6 μg/♀，与文献报道的敏感品系试虫比较，其抗性倍数分别为91.33、9.64、158.50、20.09和11.05倍。与2014年监测数据比较，抗性水平有上升趋势，对残杀威、高效氯氰菊酯、氯菊酯、溴氰菊酯分别上升>12.60、14.81、9.15和3.37倍。结论 津南区家蝇已对多种杀虫剂产生抗性，并且抗性水平呈上升趋势；建议采取可持续控制策略，以环境治理和物理防治为主，在抗药性监测数据基础上，选择抗性低的化学杀虫剂，避免长时间使用同一种药物。

关键词: 家蝇, 点滴法, 杀虫剂, 抗药性