PDMS液态防蚊膜在现场条件下对白纹伊蚊的防治效果研究

Field efficacy of polydimethylsiloxane liquid film against Aedes albopictus larvae

目的探索并评价聚二甲基硅氧烷(PDMS)液态防蚊膜在现场条件下对白纹伊蚊的防治效果及其他水生生物的影响。方法在孳生有白纹伊蚊的13个轮胎积水及5个雨水井积水中滴加不同剂量的PDMS液态防蚊膜,观察记录蚊幼死亡及发育情况等;同时观察对其他水生动物(如摇蚊幼虫)的毒性作用。结果PDMS液态防蚊膜在自然水体表面有极好的扩展性能,能够快速均匀地在水体表面形成水膜。10滴(约0.5 ml)用量对轮胎及雨水井白纹伊蚊孳生的控制作用不明显(实验组73.33 VS对照组77.14只/轮胎,t=-0.767,P=0.459);当增大防蚊膜用量后,20~80滴/轮胎(约1~4 ml)投药1 d后,投药组白纹伊蚊幼虫密度开始出现显著下降(前后对照,t=11.863,P<0.001),且投药组密度均显著低于对照组(F=71.60,P<0.001);该剂量对雨水井中白纹伊蚊作用同样显著(实验组6.38 VS对照组15.50只/500 ml水勺,t=-4.273,P=0.003)。防蚊膜的推荐使用剂量为40滴以上(约2 ml)。结论针对轮胎、雨水井等中小型孳生水体,40滴(约2 ml)以上的PDMS防蚊膜在现场使用中可有效降低白纹伊蚊孳生密度,降水对液态防蚊膜在上述两种孳生环境的作用持续时间影响明显。

Objective To evaluate the field efficacy of polydimethylsiloxane(PDMS)liquid film on Aedes albopictus larvae and the toxicity to other small aquatic insects.Methods 13 used-tires and 5 storm water catch basins breeding with Ae.albopictus larvae were treated with different dosages of PDMS liquid film,and then the larvae control effect was observed.At the same time,the toxic effects on other aquatic insects(such as chironomid larvae)were recorded.Results The PDMS liquid films could spread rapidly and create an ultrathin layer over the water surface.It was observed that 10 drops(0.5 ml)of PDMS couldn’t significantly reduce the density of Ae.albopictus larvae in the field used-tire and catch basin water(treated group 73.33 VS control group 77.14 per tire,t=-0.767,P=0.459).When the dosage of PDMS liquid film increased,it was observed that 20-80 drops(1-4 ml)of PDMS could significantly reduce the density of Ae.albopictus larvae in the field used-tire(F=71.60,P<0.001),and the density of the treated group was significantly lower than that of the control(treated group 6.38 vs.control group 15.50 per 500 ml,t=-4.273,P=0.003).The recommended dosage of the PDMS liquid was 40 drops(2 ml)per tire or catch basin.Conclusion Over 40 drops(2 ml)of PDMS liquid film per tire or catch basin can effectively reduce the density of Ae.albopictus larvae in the field breeding sites,and the precipitation could significantly reduce the efficacy of PDMS films against Ae.albopictus breeding in container water.