8种杀虫剂对云南不同区域草地贪夜蛾种群的室内毒力测定

为有效防控新入侵迁飞性害虫草地贪夜蛾,指导科学用药,本研究按照农业农村部推荐用药,在室内采用浸叶法测定了8种杀虫剂对滇西南、滇南、滇中、滇东北4个区域5个草地贪夜蛾种群3龄幼虫的毒力。测定结果表明,8种杀虫剂对上述草地贪夜蛾种群的毒力大小顺序依次为:5%甲氨基阿维菌素苯甲酸盐WG(0.05～0.09 mg/L)≥25%乙基多杀菌素WG(0.16～0.26 mg/L)5%虱螨脲SC(0.84～7.07 mg/L)20%氯虫苯甲酰胺SC(3.31～10.50 mg/L)10%虫螨腈SC(4.82～11.47 mg/L)30%茚虫威SC(23.79～40.41 mg/L)2.5%高效氯氟氰菊酯EC(102.85～147.60 mg/L)32 000 IU/mg Bt WP(141.09～352.61 mg/L),其中,甲氨基阿维菌素苯甲酸盐、乙基多杀菌素、茚虫威和Bt对4个区域种群的LD_(50)无显著性差异,虱螨脲、氯虫苯甲酰胺、虫螨腈和高效氯氟氰菊酯对4个区域种群的LD_(50)存在区域性差异,其中区域间差异显著的是5%虱螨脲SC,最大相对毒力指数为8.42倍。甲氨基阿维菌素苯甲酸盐、乙基多杀菌素、虱螨脲、氯虫苯甲酰胺和虫螨腈对草地贪夜蛾的LD_(90)均低于各药剂的田间推荐剂量,是防治草地贪夜蛾的最佳杀虫剂;茚虫威对草地贪夜蛾的LD_(90)超过了推荐剂量,选用时注意防效,高效氯氟氰菊酯和Bt不推荐作为防治药剂。研究结果为云南地区草地贪夜蛾的有效防治提供了参考。

Laboratory toxicity of eight insecticides against Spodoptera frugiperda from different areas in Yunnan

To prevent and control the new migratory pest, Spodoptera frugiperda, and guide the reasonable application of insecticides, the toxicity of eight insecticides recommended by the Ministry of Agriculture and Rural Affairs were tested against 3rd instar of S.frugiperda in by leaf dipping method. Five populations of S.frugiperda collected from southeast, south, central and northeast of Yunnan province were tested. The results showed that the toxicity ranking of these eight insecticides was: emamectin benzoate 5% WG (0.05-0.09 mg/L) > spinetoram 25% WG (0.16-0.26 mg/L)> lufenuron 5% SC (0.84-7.07 mg/L) > chlorantraniliprole 20% SC (3.31-10.50 mg/L) > chlorfenapyr 10% SC (4.82-11.47 mg/L) > indoxacarb 30% SC (23.79-40.41 mg/L)> lambda-cyhalothrin 2.5% EC (102.85-147.60 mg/L)> Bt 32 000 IU/mg WP (141.09-352.61 mg/L). Among them, the toxicity of emamectin benzoate, spinetoram, indoxacarb and Bt showed no significant difference against the five populations, while the lufenuron, chlorantraniliprole, chlorfenapyr and lambda-cyhalothrin showed different toxicities to different populations. Of which the toxicity of 5% lufenuron SC against different populations showed a variation of 8.42-fold. All five populations of S.frugiperda were sensitive to emamectin benzoate, spinetoram, lufenuron, chlorantraniliprole and chlorfenapyr with their LD90 lower than the recommended dose and were the best choice to control this pest. The indoxacarb was also active to S.frugiperda but with a higher LD90, it should be used carefully. Meanwhile, the lambda-cyhalothrin and Bt were not recommend for the control of S.frugiperda. The results of this research provided a reference for effective control of S.frugiperda in Yunnan province.