3种药剂对广东地区草地贪夜蛾3龄幼虫室内毒力测定及其田间药效评价

Study on laboratory toxicity and field efficacy of three insecticides against Spodoptera frugiperda larva in Guangdong Province

为明确几种药剂对广东地区草地贪夜蛾Spodoptera frugiperda幼虫的室内毒杀作用及田间防治效果,合理使用化学农药对草地贪夜蛾进行科学防治提供理论依据。本研究采用浸叶法测定了氯虫苯甲酰胺、高效氯氟氰菊酯和甲氨基阿维菌素苯甲酸盐对草地贪夜蛾3龄幼虫的室内毒杀作用;采用茎叶喷雾法,测定了200克/升氯虫苯甲酰胺悬浮剂、150克/升氯虫苯甲酰胺·高效氯氟氰菊酯微囊悬浮-悬浮剂、25克/升高效氯氟氰菊酯乳油和5%甲氨基阿维菌素苯甲酸盐水分散粒对田间玉米上草地贪夜蛾幼虫的防治效果。室内毒力测定试验结果表明:甲氨基阿维菌素苯甲酸和氯虫苯甲酰胺对草地贪夜蛾3龄幼虫都有较好的毒杀作用,LC 50分别为0.037 mg/L和0.094 mg/L;而高效氯氟氰菊酯对草地贪夜蛾的毒杀作用较一般,LC 50为5.336 mg/L。田间试验结果表明,供试的3种药剂对草地贪夜蛾幼虫速效性一般,药后1 d的防治效果为40.79%~59.67%;药后3 d的防治效果为67.27%~88.55%;药后7 d其防治效果为55.75%~90.97%。氯虫苯甲酰胺和甲氨基阿维菌素苯甲酸盐对草地贪夜蛾具有较好室内的毒杀作用和田间防治效果,是目前防治草地贪夜蛾的理想药剂;高效氯氟氰菊酯对草地贪夜蛾室内的毒杀作用和田间防治效果较差,不推荐用来防治草地贪夜蛾。

Nowadays,Spodoptera frugiperda is a global threat,which is distributed widely in the production fields of corn.In this study,we determined the toxicity and field control efficiency of several pesticides on S.frugiperda larvae in Guangdong Province,and also provided some evidences for scientific chemical control of S.frugiperda.The efficacy of Chlorantraniliprole,Emamectin Benzoate and Lambda-Cyhalothrin on the moth was determined by leaf immersion method.The control effects of 200 g/L Chlorantraniliprole SC,150 g/L Chlorantraniliprole·Lambda-Cyhalothrin ZC(CS SC),25 g/L Lambda-Cyhalothrin emulsion oil and 5%Emamectin Benzoate WG on the third instar larva of S.frugiperda in corn field were determined by stem-leaf spray method.The results of indoor toxicity tests showed that both Emamectin Benzoate and Chlorantraniliprole had a good effect on the third instar larva of S.frugiperda,and the LC 50 was 0.0374 mg/L and 0.094 mg/L respectively.However,Lambda-Cyhalothrin had a general effect on S.frugiperda with LC 50 of 5.34 mg/L.The results of field tests showed that the efficiency of three pesticides to S.frugiperda was general.The control effect of first day after treatment was 40.79%~59.67%.3 days after treatment was 67.27%~88.55%and 7 days after treatment was 55.75%~90.97%.Our results indicated that Chlorobenzamide and Emamectin Benzoate have better toxicity effect and field control effect on S.frugiperda.Lambda-cyhalothrin has less effective in toxicity and field test on the larva,so it is not recommended to control the S.frugiperda.