甲氨基阿维菌素苯甲酸盐对3种鳞翅目害虫与赤眼蜂的毒力

摘 要：为明确甲氨基阿维菌素苯甲酸盐对甘肃河西地区3种玉米害虫和松毛虫赤眼蜂的毒力，协调甘肃河西地区化学防治和生物防治之间的矛盾，本研究在室内采用饲喂法和药膜法分别对棉铃虫、亚洲玉米螟、粘虫和松毛虫赤眼蜂进行毒力测定。结果表明，随着甲氨基阿维菌素苯甲酸盐浓度增加，4种昆虫的校正死亡率均呈递增趋势，当药剂浓度达0.500 mg/L时，4种昆虫的校正死亡率均达95%以上。致死中浓度表明，甲氨基阿维菌素苯甲酸盐对松毛虫赤眼蜂毒力最高，致死中浓度LC50为0.078 mg/L，其次依次为亚洲玉米螟、棉铃虫和粘虫，致死中浓度LC50依次为0.109、0.120、0.127 mg/L。甲氨基阿维菌素苯甲酸盐对松毛虫赤眼蜂的毒力是其他3种鳞翅目昆虫的1.40~1.63倍。因此，综合防治中使用甲氨基阿维菌素苯甲酸盐防治害虫时，应避开赤眼蜂的出蜂时期，以降低化学杀虫剂对赤眼蜂的杀伤作用。

Toxicity of Emamectin Benzoate to 3 Kinds of Pests (Lepidoptera) and Trichogramma dendrolimi

To clarify the toxicity of emamectin benzoate to 3 kinds of pests (Lepidoptera) and Trichogramma dendrolimi in Hexi region of Gansu Province, and coordinate the contradiction between pesticide control and biological control, the toxicity of emamectin benzoate to the third instar nymphs of Lepidoptera, including cotton worm, Asia corn borer, army worm and adult Trichogramma, was measured by using diet feeding method and residual film method. The results showed that the corrected mortalities of those four insects were raised with the concentration of emamectin benzoate increasing, the mortalities were more than 95% when the concentration went up to 0.500 mg/L. The median lethal concentration indicated that the toxicity of emamectin benzoate to T. dendrolimi was the highest among the four insects, the LC50 value was 0.078 mg/L, next in turn was Asia corn borer, cotton worm and army worm, and the LC50 value was 0.109, 0.120 and 0.127 mg/L, respectively. The toxicity of emamectin benzoate to T. dendrolimi was 1.40 to 1.63 times that of the other three. Thus, in order to reduce the harm of pesticide to natural enemy Trichogramma, the use of emamectin benzoate should avoid the emergence of Trichogramma in field, especially in IPM.