Abstract:

Objective To understand the current status of insecticide resistance of housefly in Beihai city of Guangxi Zhuang Autonomous Region by molecular tools. Methods The genotypes of three genes(CYP6D1, Vssc and ace) in a field population of housefly from Beihai city were detected by polymerase chain reaction-restriction fragment length polymorphism analyses, and corresponding frequencies for each genotype were recorded. Results In 63 houseflies collected from Beihai city, no homozygote for CYP6D1 resistant allele was detected, while the frequencies of susceptible homozygotes and heterozygotes were 96.83%(61/63) and 3.17%(2/63) respectively. No 1014H mutation of Vssc was observed in these samples, but 1014F mutation was present in heterozygotes in a low frequency of 6.35%(4/63). The frequency of 1014L/L(susceptible) homozygote was very high(59/63, 93.65%). In 38 individuals, we observed two ace genotypes, namely 342G/V and 342A/V, in frequencies of 5.26% and 94.74% respectively. Notably, the frequency of resistant alleles(342A and 342V) reached 97.37%. Conclusion The frequencies of resistant alleles of both CYP6D1 (1.59%) and Vssc(3.18%) were low, suggesting that pyrethroids can be used for housefly control in this area. In contrast, extremely high frequencies of resistant alleles of ace were detected in housefly samples from Beihai city, indicating that failure may occur if using organophosphates and carbamates for control of house flies in the sampling region.

Key words: Musca domestica, Insecticide resistance, CYP6D1, Voltage-sensitive sodium channel, Acetyl cholinesterase, Beihai city

摘要：

目的 通过检测杀虫剂抗性基因频率对广西壮族自治区北海市家蝇的抗药性现状进行分析，为该地区家蝇的防治提供依据。方法 通过限制性片段长度多态性聚合酶链反应方法对野外采集家蝇的细胞色素P450 CYP6D1基因、钠离子通道基因（Vssc）和乙酰胆碱酯酶（AChE）基因（ace）进行分型，统计其基因型频率。结果 北海市的63只家蝇样本经过检测，未发现CYP6D1抗性纯合个体，而敏感纯合个体所占比例高达96.83%（61/63），杂合个体频率为3.17%（2/63），CYP6D1抗性等位基因频率仅为1.59%。在同一样本中，检测到Vssc杂合子（1014L/F）的基因频率为6.35%（4/63），敏感纯合子（1014L/L）的个体基因频率高达93.65%（59/63），未发现1014F的纯合个体及1014H突变个体。在北海市的38只家蝇样本中，检测到342G/A和342A/V两种AChE基因型个体，其频率分别为5.26%和94.74%，抗性等位基因频率总和（342A+342V）高达97.37%。结论 北海市家蝇样本中的CYP6D1和Vssc抗性等位基因频率均较低，而AChE抗性等位基因频率极高，提示目前北海市可使用拟除虫菊酯类杀虫剂防治家蝇；同时在该地区减少使用有机磷和氨基甲酸酯类杀虫剂进行灭蝇，避免家蝇种群抗性基因频率继续升高，以延缓抗性的发展。

关键词: 家蝇, 抗药性, CYP6D1, 钠离子通道, 乙酰胆碱酯酶, 北海市