【目的】 确定蜡蚧轮枝菌可分散油悬浮剂在防治枸杞棉蚜Aphis gossypii Glover的高效性和重要性，为科学安全防治枸杞棉蚜提供理论依据。【方法】 采用浸渍法测定棉蚜的室内毒力效果，利用五点取样法调查温室防治效果，通过培养箱控制温度、饱和盐溶液控制湿度测定温湿度对药效的影响。【结果】 两种蜡蚧轮枝菌可分散油悬浮剂1#和2#在处理时间为120 h的室内毒力效果最明显，LC₅₀分别为1.21×    10⁵ cfu/mL和2.08×10⁵ cfu/mL。田间施药后第14天，两种制剂各浓度间有显著性差异，防效最好的是1#制剂浓度4×10⁶ cfu/mL和2×10⁶ cfu/mL，致死率分别为97.89%和97.87%。两种制剂适应的最佳温度有差异，1#制剂发挥药效的最适温度是25 ℃和28 ℃，其第5天的校正死亡率分别为96.34%、94.09%。2#制剂发挥药效的最适温度是28 ℃，其最高校正死亡率为93.03%。两种制剂在相同相对湿度条件下无明显差异，处理5 d后，其最适宜的相对湿度是67%及以上，棉蚜死亡率达到90%以上；两种制剂在相对湿度为30%左右时的棉蚜死亡率在70%左右。总体而言，相对湿度对两种蜡蚧轮枝菌可分散油悬浮剂会产生一定的影响，但是制剂依旧会对棉蚜产生毒力。【结论】 蜡蚧轮枝菌可分散油悬浮剂对棉蚜具有良好的防治效果且温湿度影响对其药效的影响较小，可作为有效防控棉蚜种群的重要真菌杀虫剂。

[Objectives]  To determine the effectiveness of a dispersible oil suspension of Lecanicillium lecanni for the control of Aphis gossypii. [Methods]  The toxicity of the suspension to A. gossypii was determined by the impregnation method and its effectiveness in a greenhouse by the five-point sampling method. The effect of temperature and humidity on its toxicity was determined by conducting trials under controlled temperature and humidity. [Results]  Two dispersible oil suspensions of L. lecanni (1and 2) were found to be the most toxic after 120 h with LC₅₀ values of 1.21×10⁵ cfu/mL and 2.08×10⁵ cfu/mL, respectively. There was a significant difference in the concentrations of the two formulations on the 14th day after application in the field. The best protection was provided by 4×10⁶ cfu/mL and 2×10⁶ cfu/mL of formulation 1, which had a lethality of 97.89% and 97.87%, respectively. There were also differences in the optimal temperatures for the two formulations. The optimal temperatures for Formulation 1were 25 ℃ and 28 ℃, at which the adjusted mortality rates on the 5th day of 96.34% and 94.09%, respectively. The optimum temperature for Formulation 2 was 28 ℃, at which the highest corrected mortality rate was 93.03%. There was no significant difference between the two formulations under the same relative humidity conditions; the optimum relative humidity was 67% of higher 5 days after treatment at which mortality was > 90%. Mortality for both treatments was around 70% at a relative humidity of about 30%. [Conclusion]  Dispersible oil suspensions of L. lecanni are highly toxic to A. gossypii and ambient temperature and humidity have little effect on their toxicity to this pest. Such dispersible oil suspensions therefore appear to be a useful fungal insecticide for controlling A. gossypii populations.