Abstract:

Objective To determine the insecticide resistance of Culex pipiens pallens from different regions of Zhejiang province, China, to analyze the resistance phenotypes and genotypes of Cx. pipiens pallens and their association, and to provide a baseline data for the mosquito control in Zhejiang. Methods The larva dipping method was used to determine the insecticide resistance of Cx. pipiens pallens from four regions of Zhejiang province, and the genotypes were studied by PCR amplification and sequencing. Results The insecticide resistance of Cx. pipiens pallens varied greatly across different regions of Zhejiang, and beta-cypermethrin, deltamethrin, allethrin, DDVP, acetofenate, or propoxur had a median lethal concentration difference of 2.1 to 42.8 times, with the greatest variations in beta-cypermethrin. The Zhoushan strain had a significantly higher pyrethroid resistance than the strains from other regions. The pyrethroid resistance-associated vssc gene of Zhoushan strain had high polymorphism, and some samples had three neighboring fragment deletions (20 bp, 53 bp, and 40 bp) in the intron region of vssc gene. Conclusion The insecticide resistance phenotype varies greatly in Cx. pipiens pallens from different regions of Zhejiang. The kdr gene of Zhoushan strain has complex polymorphism, further study is warranted to determine whether it is the immediate cause of the change in resistance phenotype.

Key words: Culex pipiens pallens, Insecticide, Insecticide resistance, Resistance gene

摘要：

目的 对浙江省不同地区淡色库蚊抗药性水平进行调查，了解淡色库蚊的抗性表型与有关基因特征及其相关性，为浙江省蚊虫控制提供科学依据。方法 淡色库蚊抗药性表型采用幼虫浸渍法；对浙江省4个区域的淡色库蚊进行抗药性测定，基因型研究采用PCR扩增后测序确定。结果 不同地区淡色库蚊抗药性表型差异较大，对高效氯氰菊酯、溴氰菊酯、丙烯菊酯、敌敌畏、三氯杀虫酯、残杀威的半数致死浓度（LC₅₀）分别在同类药物抗性差异变化范围为2.1～42.8倍，其中以高效氯氰菊酯抗性差异最高。舟山种群拟除虫菊酯类药物抗性水平明显高于其他地区，其拟除虫菊酯抗性相关基因vssc基因具有较高多态性，部分样本vssc基因内含子区域出现3个紧邻的大小分别为20、53和40 bp的片段缺失。结论 浙江省不同地区淡色库蚊抗性表型差异较大，抗性基因监测发现舟山种群kdr基因存在较复杂的多态性，是否为导致其抗性表型变化的直接原因还有待进一步研究证实。

关键词: 淡色库蚊, 杀虫剂, 抗药性, 抗性基因