2017年石家庄市乙脑高发区赵县淡色库蚊抗药性调查

Investigation on resistance of Culex pipiens pallens in Zhao County,a high incidence areas of epidemic encephalitis type B in Shijiazhuang in 2017

目的了解石家庄市乙脑高发区赵县淡色库蚊对常用杀虫剂的抗药性水平,为合理选择杀虫剂防控蚊媒传染病提供依据。方法幼虫采用浸渍法,测定不同浓度杀虫剂下淡色库蚊的死亡率,计算半数致死浓度(LC_(50))和抗性倍数RR(抗性品系蚊虫的LC_(50)/敏感品系蚊虫的LC_(50));成虫采用接触筒法测定不同浓度杀虫剂下淡色库蚊的死亡率。结果幼虫对醚菊酯抗性为高抗,对联苯菊酯抗性为高抗,对吡丙醚的抗性为中抗,抗性倍数分别为566倍、56.25倍和11.90倍。成虫对溴氰菊酯、氯菊酯、残杀威的死亡率均小于80%,均为抗性种群。结论石家庄市赵县的淡色库蚊对拟除虫菊酯类和氨基甲酸酯类杀虫剂抗药性程度较高,对昆虫生长调节剂抗性较低,为控制蚊传疾病降低蚊虫密度,可采用两种或几种作用机理不同的杀虫剂轮换使用的措施,合理使用杀虫剂。

Objective The aim was to understand the resistance level of Culex pipiens pallens to commonly used insecticides in Zhao County,a high incidence area of epidemic encephalitis type B in Shijiazhuang,and to provide a basis for rationally selecting insecticides to prevent and control mosquito-borne diseases.Methods Larvae dipping methods and adult contact methods were adopted for the bioassay.The mortality of Culex pipiens pallens under different concentrations of insecticide was measured.The lethal concentration of 50%(LC_(50))and resistance ratio(LC_(50) of resistant strain mosquitoes versus LC_(50) of sensitive strain mosquitoes)were calculated.Results The larvae were highly resistant to permethrin and bifenthrin and moderately resistant to pyriproxyfen,with resistance ratios of 566 times,56.25 times and 11.90 times respectively.The mortality of adults to deltamethrin,permethrin and propoxur was less than 80%,all of which were resistant species.Conclusion Culex pipiens pallens in Zhao County,Shijiazhuang have a high level of resistance to pyrethroids and carbamates and a low level of resistance to insect growth regulators.In order to control mosquito-borne diseases and reduce mosquito densities,two or more insecticides with different action mechanisms can be used in rotation to rationalize the use of insecticides.