海南省部分地区传疟媒介按蚊对4种常用杀虫剂的抗药性测定

Resistance Assay of Malaria Vectors to Four Kinds of Common Insecticides in Some Endemic Areas of Hainan Province

目的了解海南省部分地区传疟媒介按蚊对4种常用杀虫剂的抗药性。方法于2008-2010年在多年使用杀虫剂防治疟疾的高疟区昌江县王下乡和东方市江边乡采集媒介按蚊,在昌江县王下乡以人诱法采集大劣按蚊,在东方市江边乡采用牛诱法采集中华按蚊和微小按蚊。取F0代中华按蚊雌蚊、F1代微小按蚊和大劣按蚊雌蚊为测试蚊虫,采用WHO成蚊滤纸接触筒法测定上述测试蚊虫接触4%DDT(1.428g/m2)、0.05%溴氰菊酯(0.0178g/m2)、0.15%氟氯氰菊酯(0.053 4 g/m2)和5%马拉硫磷(1.78 g/m2)等4种杀虫剂的区分剂量60 min内的击倒率,同时设空白对照组。计算半数击倒时间(KT50)和24 h后死亡率,以区分剂量判定抗性级别。结果 DDT、溴氰菊酯和马拉硫磷对大劣按蚊的死亡率均为100%;DDT和溴氰菊酯对大劣按蚊的击倒率分别为82.0%和100%,KT50值分别为46.9 min和18.4 min。DDT、溴氰菊酯、氟氯氰菊酯和马拉硫磷对微小按蚊的死亡率分别为98.1%、99.0%、100%和100%;DDT、溴氰菊酯、氟氯氰菊酯对微小按蚊的击倒率分别为96.3%、99.0%和100%,KT50值分别为31.3 min、16.8 min和7.4 min。DDT、溴氰菊酯和马拉硫磷对中华按蚊的死亡率分别为19.8%、22.9%和43.8%;DDT和溴氰菊酯对中华按蚊的击倒率仅为2.0%,不能测定其KT50。结论本次测试的海南省部分地区的主要传疟媒介大劣按蚊和微小按蚊对常用杀虫剂DDT、溴氰菊酯、马拉硫磷和氟氯氰菊酯等未产生抗药性,而次要媒介中华按蚊对DDT、溴氰菊酯和马拉硫磷有抗药性。

Objective To determine the resistance of malaria vectors to four kinds of common insecticides in some endemic areas of Hainan Province.Methods Anopheline mosquitoes were collected between 2008 and 2010 from malaria endemic areas where insecticides were used for years.Anopheles dirus were collected from human-baited trap in Wangxia Town of Changjiang County.An.minimus and An.sinensis were collected by cow-baited trap in Jiangbian Town of Dongfang City.F0 generation female An.sinensis,F1 generation of female An.dirus and An.minimus were selected and exposed to insecticide impregnated papers with discriminating concentrations of DDT（4%）,deltamethrin（0.05%）,cyfluthrin（0.15%）,and malathion（5%） using WHO standard assays.Knockdown rate was recorded at 10,15,20,30,40,50,and 60 min,and KT50 values were calculated.Mortality was recorded after 24 hours of exposure.Results Mortality in An.dirus was 100% to DDT,deltamethrin and malathion.Knockdown rate of An.dirus exposed to DDT and deltamethrin was 82.0% and 100%,with a KT50 value of 46.9 and 18.4 min,respectively.Mortality of An.minimus to DDT,deltamethrin,cyfluthrin and malathion was 98.1%,99.0%,100%,and 100%,respectively.The knockdown rate of An.minimus to DDT,deltamethrin,and cyfluthrin was 96.3%,99.0%,and 100%,respectively,and the KT50 value was 31.3,16.8,and 7.4 min,respectively.Mortality of An.sisensis to DDT,deltamethrin,and malathion was 19.8%,22.9%,and 43.8%,respectively.Knockdown rate of An.sisensis to DDT and deltamethrin was 2.0%,the KT50 can not be calculated.Conclusion An.dirus and An.minimus,the main malaria vectors in the survey sites of Hainan Province,are susceptible to the four insecticides,while secondary malaria vector An.sinensis showed resistance to DDT,deltamethrin,and malathion.