京郊西兰花小菜蛾的田间防治药剂筛选与评价

为评价高效氯氰菊酯、溴氰虫酰胺、苏云金杆菌、甲氨基阿维菌素苯甲酸盐、乙基多杀菌素等5种杀虫剂对小菜蛾的田间药效,本文采用喷雾法进行了田间试验。结果表明,10%溴氰虫酰胺可分散油悬浮剂、6%乙基多杀菌素悬浮剂对小菜蛾在药后1~7 d的防效较好;32000 IU/mg苏云金杆菌可湿性粉剂、32000 IU/mg苏云金杆菌可湿性粉剂与10%溴氰虫酰胺可分散油悬浮剂分别按50%推荐用量组成的1∶1的混配剂,药后1 d的防效仅在60%左右,速效性较差,但是药后3~7 d的防效较好。其中,混配剂药后3 d的防效高达90.70%。5%甲氨基阿维菌素苯甲酸盐水分散粒剂和4.5%高效氯氰菊酯乳油在药后1~7 d的防效均较差。因此,在西兰花生产上可使用减量的溴氰虫酰胺与苏云金杆菌混配剂进行小菜蛾的防治,以达到农药减量增效防治小菜蛾的目的;在小菜蛾暴发时,可使用溴氰虫酰胺或乙基多杀菌素,以达到迅速防治的目的。

Screening and evaluation of the field efficacies of insecticides against Plutella xylostella on Brassica oleracea var. italica in suburban of Beijing

This study aims to evaluate the field efficacies of five insecticides,beta-cypermethrin,cyantraniliprole,Bacillus thuringiensis,emamectin benzoate and spinetoram,against Plutella xylostella L.Field efficacy trials were conducted by spraying.The results showed that cyantraniliprole 10%OD and spinetoram 6%EC exhibited high field control efficacies against P.xylostella 1-7 d after treatment.Bacillus thuringiensis 32000 IU/mg WP,and its 1∶1 mixture with cyantraniliprole 10%OD at half of the recommend dose showed around 60%of field control efficacy one day after treatment,indicating their fast action effect wasn’t so good.However,good control effects were observed three and seven days after treatments.Especially,the control efficacy the mixture of Bacillus thuringiensis 32000 IU/mg WP and cyantraniliprole 10%OD is as high as 90.70%.The efficacies of emamectin benzoate 5%WG and beta-cypermethrin 4.5%EC against P.xylostella were poor 1-7 d after treatment.Therefore,the mixture of cyantraniliprole and B.thuringiensis can be used for the control of P.xylostella on Brassica oleracea,which can reduce the application dose of chemical insecticide to some extent.When P.xylostella is outbreak,cyantraniliprole or spinetoram can be used for emergency control.