Abstract:

Objective To determine the susceptibility of larvae and adults of a laboratory strain of Anopheles sinensis to the commonly used insecticides, and to provide a reference for comparison among field populations. Methods The insecticide resistance of An. sinensis laboratory strain was evaluated under laboratory condition with the WHO recommended bioassay on larvae and adults. Data were analyzed using Probit regression to determine LC₅₀ values. Results The mortality of An. sinensis adults exposed for 1 hour to the following insecticides was 56.5% to 4% DDT, 100% to 0.025% and 0.05% deltamethrin, 0.05% beta-cypermethrin, as well as 0.25% and 0.75% permethrin, while mortality to 0.025% beta-cypermethrin was slightly lower (99.6%). The susceptibility of An. sinensis larvae to deltamethrin, beta- cypermethrin, permethrin, temephos, spinosad, and dinotefuran as expressed by LC5(0 95%CI)was 0.0025(0.0021-0.0030), 0.0047(0.0035-0.0062), 0.0190(0.0156-0.0224), 0.1125(0.0921-0.1407), 0.0047(0.0035-0.0062), and 0.1744 (0.1653-0.1840)mg/L, respectively. Conclusion The laboratory strain of An. sinensis from National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention has showed reduced susceptibility to DDT, but remains susceptible to the commonly used pyrethroids as shown by bioassay data in adults. The actual resistance ratios in larvae and adults to the insecticides tested can be determined by comparing with known reference populations in the future if desired.

Key words: Anopheles sinensis, Laboratory strain, Insecticide resistance, Bioassay

摘要：

目的 研究实验室品系中华按蚊成蚊及幼虫对常用杀虫剂的敏感性,为中华按蚊的抗药性测定和比较提供参考品系。方法 测定成蚊抗药性水平参考WHO对按蚊的诊断剂量使用接触筒法;测定幼虫对双硫磷、溴氰菊酯、高效氯氰菊酯、氯菊酯、多杀菌素、呋虫胺的半数致死浓度(LC₅₀)及其95%置信限(95%CI)使用WHO推荐的浸渍法。结果 中华按蚊成蚊对4%DDT(1 h)死亡率为56.5%;对0.05%溴氰菊酯(1 h)、0.05%高效氯氰菊酯(1 h)和0.75%氯菊酯(1 h)死亡率均为100%,对0.025%溴氰菊酯(1 h)、0.025%高效氯氰菊酯(1 h)和0.25%氯菊酯(1 h)死亡率分别为100%、99.6%和100%;中华按蚊幼虫对溴氰菊酯、高效氯氰菊酯、氯菊酯、双硫磷、多杀菌素、呋虫胺的LC₅₀ 值(95% CI)分别为0.0025(0.0021～0.0030)、0.0047(0.0035～0.0062)、0.0190(0.0156～0.0224)、0.1125(0.0921～0.1407)、0.0047(0.0035～0.0062)和0.1744(0.1653～0.1840)mg/L。结论 本实验室品系中华按蚊成蚊对拟除虫菊酯类杀虫剂敏感,对DDT有抗性。

关键词: 中华按蚊, 实验室品系, 抗药性, 生物测定