Abstract: Objective To test the control effects against mosquitoes of ultra-low volume (ULV) spraying of insecticide formulations at various dilution rates and droplet sizes as well as the effective utilization rate of insecticides at various droplet sizes,and to provide a scientific basis for the use of ULV spraying and insecticides.Methods A laser particle size analyzer was used to measure the particle size and differential and cumulative particle-size distributions of ULV spray droplets of insecticide formulations.The control efficacy against Aedes albopictus of Aqua Resigen (S-bioallethrin+permethrin,104 g/L) sprayed at various dilution rates and droplet sizes was tested by hanging cage method under field indoor conditions.SAS 9.2 software was used for one-way analysis of variance.Results When using the ULV1 sprayer to apply Aqua Resigen after 10-,30-,and 50-fold dilution under the label-recommended dose of 0.012 5 mL/m³,the 24-h mortalities of Ae.albopictus were 74.03%,72.95%,and 79.82%,respectively,with no statistical difference (F=0.260,P=0.781).When the sprayer was changed from ULV1 to ULV2 to decrease the droplet size from 80.89µm to 38.28µm,the effective utilization rate of Aqua Resigen was increased from 20.48% to 76.89%,and the mortality was increased from 74.03% to 99.47%.When the test dose of Aqua Resigen was reduced to 0.006 25 mL/m³,ULV2 spraying conferred a 24-h mortality of Ae.albopictus of 98.27%.Conclusion Within a certain dose range,the dilution rate for ULV spraying of the insecticide formulation can be adjusted according to actual needs,which has little impact on the control of mosquitoes.However,the size of ULV spray droplets greatly affects the performance of the insecticide formulation.Increasing the proportion of droplets smaller than 50 μm can improve the control effect and reduce the waste of insecticides.

Key words: Ultra-low volume sprayer, Aedes albopictus, Insecticide formulation, Dilution rate, Droplet size, Control efficacy

摘要： 目的 测试杀虫剂不同稀释倍数和雾滴粒径对超低容量（ULV）喷雾控制蚊虫的效果，以及不同雾滴粒径时杀虫剂的有效利用率，为ULV和杀虫剂的使用提供科学依据。方法 采用激光粒度仪测量ULV的雾滴粒径、粒度的微积分分布和累积分布；用挂笼法在现场室内条件下，测试列喜镇^®（S-生物烯丙菊酯·氯菊酯104 g/L）的不同稀释倍数及喷洒雾滴粒径对白纹伊蚊防控效果的影响。采用SAS 9.2软件进行单因素方差分析。结果 使用ULV1喷雾器，在标签推荐使用剂量0.012 5 ml/m³下，分别用10、30和50倍稀释后的列喜镇^®喷洒，挂笼中白纹伊蚊的24 h死亡率分别为74.03%、72.95%和79.82%，差异无统计学意义（F=0.260，P=0.781）；当喷雾器由ULV1换成ULV2时，雾滴粒径从80.89 µm降到38.28 µm，杀虫剂有效利用率从20.48%提高到76.89%，防控效果从74.03%提高到99.47%。将杀虫剂的测试剂量降低至0.006 25 ml/m³，用ULV2喷雾器施药，24 h白纹伊蚊的死亡率为98.27%。结论 ULV喷洒杀虫剂，在一定施药剂量下，稀释倍数可以根据实际需要做适当调整，其对蚊虫的防控效果影响不大；但是ULV喷雾器喷出的雾滴粒径大小对杀虫剂的防控效果影响很大，增加50 µm以下雾滴所占比例可提高杀虫剂的防控效果，同时减少药剂的浪费。

关键词: 超低容量喷雾器, 白纹伊蚊, 杀虫剂, 稀释倍数, 雾滴粒径, 防控效果