武汉市登革热媒介白纹伊蚊对常用杀虫剂的敏感性研究

目的 了解武汉市白纹伊蚊常用的化学杀虫剂、生长调节剂及部分生物杀虫剂对野外白纹伊蚊幼虫的敏感性,为当地白纹伊蚊的防控提供科学依据。方法 采集武汉市白纹伊蚊野外种群,经实验室鉴定计数,白纹伊蚊幼虫 1 847只,蛹302只,实验室饲养至F₁代,试虫为F₁代三龄幼虫。采用幼虫浸渍法测定幼虫对不同杀虫剂（96.85%溴氰菊酯、99.00%氯菊酯、87.40%双硫磷、95.56%残杀威、97.00%吡丙醚、95.00%S-烯虫酯、98.70%除虫脲）及 7 000 ITU/mg Bti对白纹伊蚊的敏感性;白纹伊蚊二龄幼虫被武昌罗索线虫寄生后,每天统计幼虫死亡情况,绘制存活曲线。结果 武汉市白纹伊蚊幼虫对双硫磷、溴氰菊酯、氯菊酯、残杀威LC₅₀分别为0.023 40、0.036 37、0.200 0、1.562 9 mg/L,对双硫磷和溴氰菊酯较为敏感。对S-烯虫酯、吡丙醚和除虫脲IE₅₀分别为0.000 310、0.000 412、0.009 594 mg/L,对S-烯虫酯和吡丙醚较为敏感。Bti对白纹伊蚊LC₅₀为0.002 697 mg/L,在蚊幼虫∶线虫=1∶5和1∶10的感染比例时,蚊幼虫死亡率分别为77.42%和95.04%,与对照组比较差异有统计学意义（P<0.000 1）。结论 武汉市白纹伊蚊幼虫防控时,双硫磷、溴氰菊酯可作为快速杀灭手段,也可以选用S-烯虫酯和吡丙醚等生长调节剂。同时,生物测定表明生物防治剂武昌罗索线虫对白纹伊蚊幼虫也有较好的防控效果。

Study on the sensitivity of Aedes albopictus to common insecticides in Wuhan

Objective To investigate the sensitivity of A. albopictus to commonly used insecticides in Wuhan, providing the guidance in the control of mosquitoes. Methods A total of 1 847 larvae and 302 pupae were collected from the field population of Ae. albopictus in Wuhan. The larvae were reared to F1 generation in the laboratory, and the larvae were the third instar larvae of F1 generation. The sensitivity of larvae to different insecticides (96.85% deltamethrin, 99.00% permethrin, 87.40% disphos, 95.56% propoxur, 97.00% pyripropyl ether, 95.00% S-enyl ester, 98.70% difenuron) and 7 000 ITU / mg Bti were determined by immersion method. After the second instar larvae of Aedes albopictus were parasitized by Nematode Wuchang, the death rate of larvae was calculated and the survival curve was drawn. Results The median lethal concentration (LC₅₀) of the larvae against temephos, deltamethrin, permethrin and propoxur were 0.023 40, 0.036 37, 0.200 0 and 1.562 9 mg/L respectively, relative sensitive to temephos and deltamethrin. The inhibition emergence concentration (IE₅₀) of the larvae against S-methoprene, pyriproxyfen and diflubenzuron were 0.000 310, 0.000 412, and 0.009 594 mg/L, respectively, relative sensitive to S-methoprene and pyriproxyfen. The LC₅₀ of the larvae against Bti was 0.002 697 mg/L, and the mortality rates of mosquito larvae were 77.42% and 95.04% at the infection ratio of mosquito larvae to nematodes=1∶5 and 1∶10, respectively, which were highly significantly different from the control group (P<0.000 1). Conclusions Temephos and deltamethrin can be used as a quick method to control A. albopictus larvae in Wuhan city, and the insect growth regulators such as S-methoprene and pyriproxyfen also can be used as an environmentally friendly insecticides. R. wuchangensis is also highly efficient for mosquito larvae control.