氯菊酯浸泡粗网眼蚊帐防制蚊虫效果观察

Observation on the Effectiveness of Permethrin—impregnated Wide Mesh Bednet against Mosquitoes

实验观察:取体积为25×20×19cm^3的蚊笼两个,各拆去一边后重新组合成双体蚊笼。在双体笼的一侧放4d 龄饥饿雌蚊50只,另一侧放一只绑在木板上,已剃除腹毛的小鼠作为诱饵,中间用经氯菊酯0.1g/m^2浸泡的粗网眼(直径5mm)帐纱隔开,观察蚊虫通过网眼的情况。同时设立对照组。结果嗜人按蚊和埃及伊蚊药物组2h 内通过率分别为25.17%和9.09%,对照组分别为48.39%和40.47%;嗜人按蚊和埃及伊蚊药物组的吸血率分别为0.29%和0,而对照组两种蚊虫的吸血率均为100%。现场实验:在贵州省安顺地区进行。取上述粗网眼帐纱制成面积为10.6m^2的蚊帐两顶,其中一顶用氯菊酯0.1g/m^2浸泡,另一顶用清水浸泡作为对照。将上述两顶蚊帐分别悬挂于条件相同,门窗密闭的两间卧室内,帐内各睡一人。傍晚在两间卧室内同时释放由孳生地采集的蛹羽化后4d 的饥饿致倦库蚊,通宵在帐内捕捉由网眼进入的蚊虫。结果药帐组蚊虫的通过率和24h 死亡率分别13.04%和100%,对照组分别为55.37%和1.90%。夜间于田野将上述两顶蚊帐挂在两张床上,两床距离为3m 左右,床上各睡一人,另外两人在帐外通宵捕捉停落于蚊帐上的蚊虫,翌日鉴定蚊种并检查死亡率。结果停落于药帐和无药帐的蚊数分别为47只和538只,蚊虫死亡率分别为100%和2.79%。以上结果表明,经氯菊酯0.1g/m^2浸泡的粗网眼蚊帐,具有减少蚊虫停落,防止蚊虫吸血和杀死蚊虫的作用,但残效只有5周左右,这一灭蚊措施值得进一步研究。

LABORATORY OBSERVATION: Two specially made big mosquito cages about 50×20×19cm^3 in size were usedin the test.Each was composed of two small cages named as cage A and cage B.A piece of wide-mesh bednet was placed between.The size of the mesh was about 5mm in diameter. The bednet used for the test group was impregnated with permethrin a.i. 0.1g/m^2.Fifty unfed female mosquitoes of 4-day-old were released into the cage A.A hair-cleaned mouse was bound in the cage B.Observation on the pass-through of the mosquitoes was then conducted.It was found that during a period of 2 hours,the pass-through ratios of Anopheles anthropophagus and Aedes aegypti in the test groups were 25.17% and 9.09%,while those in the control groups were 48.39% and 40.47%,respecti- vely.The blood-sucking ratios of An.anthropophagus and Ae.aegypti in the test groups were 0.92% and 0,whereas in the control groups those of both species were 100% FIELD TRIAL:Field trial was carried out in Guizhou Province.Two bednets made from the same materials mentioned above were used.The one impregnated with permethrin a.i.0.1g/m^2-was used in the test group. The other dealt only with water was used as the control.The total surface area of a bednet was about 10.0m^2.They were hung respectively in two closed rooms with same conditions.A person stayed inside each bednet, Four-day-old unfed Cx.quinquefasciatus,which emerged from the pupae collected from local breeding sites,were released into the rooms in the evening.When passed through the bednets the mosquitoes were caught. The operation was eonducted during the whole night.It was showed that the pass-throagh ratio and the mortality of the mosquitoes in the teat group were 13.94% and 100%,while in the control group they were 55.67% and 1.90%,respectively.In addition,two beds with 3m apart were put outside the house,and each was surrounded by a bednet.Inside the bednet slept- a person.When the mosquitoes landed on the bednet,they were caught by the observers outside,and identified next morning.It was found that the numbers of mosqitoes landed on the bednets in the test and the control group were 47 and 538,and the mortality were 100% and 2.79%,respectively. The results of our study suggested that the wide-mesh bednet impre- hated with permethrin a.i.0.1g/m^2 canprevent mosquitoes from the landi- ng on the bednet,decrease the ratio of blood-sucking and kill them with a residual effectiveness of about five weeks.It is considered that this technique is worthy of further study.