三种杀虫剂对烟粉虱优势寄生蜂海氏桨角蚜小蜂的安全性评价

为评价噻虫嗪、阿维菌素和氟啶虫胺腈对烟粉虱优势寄生蜂海氏桨角蚜小蜂Eretmocerus hayati的安全性,采用琼脂保湿浸叶法分别测定了3种杀虫剂对烟粉虱成虫和海氏桨角蚜小蜂成蜂的室内毒力以及对海氏桨角蚜小蜂蛹羽化率的影响.结果表明,噻虫嗪、阿维菌素和氟啶虫胺腈对烟粉虱的LC50分别为453.76 mg/L、2.00 mg/L和29.47 mg/L,对海氏桨角蚜小蜂成蜂的LC50分别为0.23 mg/L、1.07 mg/L和0.64 mg/L.通过风险系数评估,表明阿维菌素对海氏桨角蚜小蜂成蜂安全,而噻虫嗪和氟啶虫胺腈对该蜂成蜂具有轻微到中度毒性.3种杀虫剂在烟粉虱和寄生蜂之间的选择性毒力指数表明噻虫嗪对海氏桨角蚜小蜂的负向选择性最强,其次是氟啶虫胺腈,阿维菌素最弱.3种杀虫剂均可显著降低海氏桨角蚜小蜂蛹的羽化率,对蛹的毒性为轻微有害,风险等级为2级.本研究结果将为烟粉虱综合治理中协调使用寄生蜂和化学药剂奠定理论基础.

Safety evaluation of three insecticides on Eretmocerus hayati, a dominant parasitoid of Bemisia tabaci

To evaluate the safety of three insecticides (thiamethoxam, abamectin and sulfoxaflor)on Eretmocerus hayati, a dominant parasitoid of Bemisia tabaci, the toxicity of three insecticides against B. tabaci and Er. hayati were determined by leaf dipping method. The LC50 of thiamethoxam, abamectin, sulfoxaflor to B. tabaci were 453.76 mg/L, 2.00 mg/L and 29.47 mg/L, and to Er. hayati were 0.23 mg/L, 1.07 mg/L and 0.64 mg/L, respectively. According to the risk quotient analysis, abamectin was safe to the adults of Er. hayati , while thiamethoxam and sulfoxaflor were slightly to moderately toxic to the adults of Er. hayati. The selectivity toxicity ratio of the three insecticides between B. tabaci and Er. hayati showd that the negative selectivity of thiamethoxam was the highest, followed by sulfoxaflor and abamectin. All three insecticides could significantly reduce the emergence rate of the pupae of Er. hayati, and they were slightly harmful(class 2)to the pupae of Er. hayati. Our results provide new insight in how to coordinate parasitoids and insecticides in IPM system of B. tabaci.