5种杀虫剂对粘虫不同发育阶段的室内毒力
Indoor Toxicity Determination of Five Kinds of Insecticides on Mythimna separata (Walker) at Different Developmental Stages

采用胃毒法、卵和蛹采用浸渍法，测定甲氨基阿维菌素苯甲酸盐、氯虫苯甲酰胺、辛硫磷、联苯菊酯、高效氯氟氰菊酯5种杀虫剂对粘虫卵、1龄幼虫、3龄幼虫、5龄幼虫和蛹的室内毒杀作用。结果表明：供试5种杀虫剂对卵的触杀作用依次为甲氨基阿维菌素苯甲酸盐＞高效氯氟氰菊酯＞联苯菊酯＞辛硫磷＞氯虫苯甲酰胺；对幼虫的毒杀作用依次为甲氨基阿维菌素苯甲酸盐＞联苯菊酯、高效氯氟氰菊酯＞氯虫苯甲酰胺＞辛硫磷；对蛹的触杀作用依次为高效氯氟氰菊酯＞联苯菊酯＞辛硫磷＞甲氨基阿维菌素苯甲酸盐＞氯虫苯甲酰胺。甲氨基阿维菌素苯甲酸盐对粘虫卵和幼虫的毒杀效果最好，对卵、1龄幼虫、3龄幼虫、5龄幼虫的LC50分别为0.276、1.555、0.109和1.483 mg/L；高效氯氟氰菊酯对粘虫蛹的触杀效果最好，LC50为5.539 mg/L。建议根据粘虫发生的实际情况，在生产中将甲维盐和高效氯氟氰菊酯作为防治粘虫的首选药剂。与其他供试的4种杀虫剂相比，氯虫苯甲酰胺对粘虫卵和蛹的毒杀作用最弱，对1龄、3龄、5龄幼虫的毒杀作用略高于辛硫磷或与其相当，显著低于联苯菊酯、高效氯氟氰菊酯和甲氨基阿维菌素苯甲酸盐，建议在粘虫大发生时慎用。
The toxicities of emamectin benzoate, chlorantraniliprole, phoxim, bifenthrin, cyhalothrin against the eggs,1st instar larvae, 3rd instar larvae,5th instar larvae and pupae of Mythimna separata (Walker) were measured. And the toxicities of the above insecticides against larvae were tested by stomach toxicity method and dipping method in eggs and pupae respectively in the laboratory. The results showed that contacting toxicities on the eggs and pupae of oriental armyworm was in the order of emamectin benzoate> cyhalothrin> bifenthrin> phoxim> chlorantraniliprole and cyhalothrin> bifenthrin> phoxim> emamectin benzoate> chlorantraniliprole, respectively, and the stomach toxicities on the larvae were emamectin benzoate> bifenthrin, cyhalothrin > chlorantraniliprole > phoxim. Emamectin benzoate was the most efficient insecticide to the larvae and pupae of oriental armyworm,while the LC50 for eggs,1st instar larvae, 3rd instar larvae and 5th instar larvae was 0.276 mg/L, 1.555 mg/L, 0.109 mg/L and 1.483 mg/L, respectively. Cyhalothrin had strongest contact toxicities on pupae with the LC50 5.539 mg/L. Thus, we suggest that emamectin benzoate and cyhalothrin can be the first choice to control oriental armyworm based on the actual situation in production. However the toxicity of chlorantraniliprole on the eggs and pupae was weakest in the five kinds of insecticides and its effect on the larvae was equivalent to phoxim. So when oriental armyworm outbreaks, chlorantraniliprole should not be used in the field．