苏州市三带喙库蚊对常用杀虫剂的抗药性调查

Resistance of Culex tritaeniorhynchus to commonly used pesticides in Suzhou

目的了解江苏省苏州市流行性乙型脑炎(乙脑)媒介三带喙库蚊对常用杀虫剂的抗药性现状。方法采用浸渍法测定苏州市三带喙库蚊现场种群对溴氰菊酯、高效氯氰菊酯、氯菊酯、生物烯丙菊酯、敌敌畏和残杀威的半数致死浓度(LC50),以判定抗性等级。结果苏州市三带喙库蚊对敌敌畏、残杀威、溴氰菊酯、高效氯氰菊酯、氯菊酯和生物烯丙菊酯的LC50分别为2.4691、7.7017、0.0424、0.1137、0.2659和0.6698mg/L;三带喙库蚊除对生物烯丙菊酯中抗外,对其他5种杀虫剂均为高抗,且对3种拟除虫菊酯类抗性倍数均超过50倍,甚至达100倍。结论针对各地三带喙库蚊对多种杀虫剂均产生低等或更高程度抗药性的现状,三带喙库蚊的防治应采取以环境治理和生物防治为主,化学防治为辅的综合治理措施,注重统筹用药和农业合理规划;当三带喙库蚊密度高或有乙脑疫情时,应加强化学防治,做到科学合理用药。

Objective To determine the current resistance of Culex tritaeniorhynchus, vector of Japanese encephalitis （JE）, to commonly used pesticides in Suzhou city, Jiangsu province. Methods Using the dipping method, the median lethal concentration （LC50） values of deltamethrin, betacypermethrin, permethrin, biothrin, dichlorovos and propoxur were measured for the field population of Cx. tritaeniorhynchus in Suzhou city. Results The LC50 values of deltamethrin, betacypermethrin, permethrin, biothrin, dichlorovos and propoxur for Cx. tritaeniorhynchus were 0.0424, 0.1137, 0.2659, 0.6698, 2.4691 and 7.7017 mg/L, respectively. Intermediately resistant to biothrin, the strain was highly resistant to the other five agents with resistance ratios of more than 50, even 100, to the three pyrethroids. Conclusion In view of the low or higher resistance of Cx. tritaeniorhynchus to multiple pesticides, environmental and biological strategies in conjunction with auxiliary chemical approaches should be deployed for better control of this vector. Administration of pesticides and rational agricultural planning should be carried out based on the big picture. In the event of skyrocketing mosquito density or occurrence of JE epidemic, pesticides should be scientifically distributed and chemical control approaches intensified.