不同杀虫剂对油菜花露尾甲成虫的室内毒力测定及田间防效

为筛选出防治陕西省冬油菜区油菜花露尾甲高效安全的杀虫剂，选用5%高效氯氟氰菊酯水乳剂、25%溴氰菊酯乳油、20%呋虫胺水分散粒剂、30%噻虫嗪悬浮剂、10%溴氰虫酰胺可分散油悬浮剂、20%氯虫苯甲酰胺等6种杀虫剂，采用浸虫法和田间小区试验分别对油菜花露尾甲进行了室内毒力测定和田间防效评价。结果表明：6种药剂对油菜花露尾甲均有较高的毒力，24 h的LC₅₀值均低于40 mg/L，其中20%呋虫胺WG毒力最强，10%溴氰虫酰胺OD次之，30%噻虫嗪SC毒力最弱，LC₅₀分别为5.236 mg/L、9.650 mg/L和35.078 mg/L，6种杀虫剂毒力大小排序：20%呋虫胺WG>10%溴氰虫酰胺OD>25%溴氰菊酯EC>20%氯虫苯甲酰胺SC>5%高效氯氟氰菊酯EW>30%噻虫嗪SC。田间防效试验结果表明，6种药剂在试验剂量下使用安全无药害，对油菜花露尾甲均有一定的防效，药后1 d、3 d、7 d各处理防效分别达79.3%~91.25%、88.24%~97.95%、72.47%~98.86%，其中20%呋虫胺WG3 000倍液和10%溴氰虫酰胺OD4 000倍液效果最好，20%呋虫胺WG3 000倍液3 d时防效是所有处理中最高的（97.95%），10%溴氰虫酰胺OD4 000倍液7 d时防效是所有处理中最高的（98.86%），且两种杀虫剂药后1 d、3 d、7 d的防效均在85%以上。生产中选择防治油菜花露尾甲药剂应兼具速效性、持效性和对传粉益虫蜜蜂安全，可选20%呋虫胺WG或10%溴氰虫酰胺OD在现蕾未开花时使用，20%氯虫苯甲酰胺SC在油菜进入花期后使用。

Toxicity and Field Efficacy of Different Insecticides Against Adults of Brassicogethes aeneus Fabricius

In order to screen out highly effective and safe insecticides against Brassicogethes aeneus Fabricius in the winter rapeseed area of Shaanxi Province, six insecticides were evaluated through both laboratory toxicity tests and field trials.The six insecticides tested were 5% Lambda-cyhalothrin EW, 25% Deltamethrin EC ,20% Dinotefuran WG ,30% Thiamethoxam SC,10% Cyantraniliprole OD and 20% Chlorantraniliprole SC.The toxicity test was conducted using insect dipping method, and the control efficacy of these insecticides was evaluated through field plot trials.The toxicity results showed that all the six insecticides exhibited higher toxicity against Brassicogethes aeneus F. The LC₅₀ values of all treatments were lower than 40mg/L at 24h. Among the tested insecticides,20% Dinotefuran WG exhibited the highest toxicity against Brassicogethes aeneus F. with an LC₅₀ value of 5.236mg/L, followed by 10% Cyantraniliprole OD with an LC₅₀ of 9.650mg/L.The least toxic was 30% Thiamethoxam SC,which had the lowest toxicity with the LC₅₀ value of 35.078mg/L at 24h.The toxicity order of six insecticides was as follows: 20% Dinotefuran WG>10% Cyantraniliprole OD>25% Deltamethrin EC>20% Chlorantraniliprole SC>5% Lambda-cyhalothrin EW>30% Thiamethoxam SC.The results of field control test showed that the six insecticides were safe and harmless at the test dosage,and had certain control efficacy on the Brassicogethes aeneus F.At 1 day,3 days and 7 days after treatment, the control efficacies were 79.3%~91.25%,88.24%~97.95%,72.47%~98.86%, respectively. The 3 000 times of 20% Dinotefuran WG and 4 000 times of 10% Cyantraniliprole OD showed the optimal control efficacies among all the six insecticides. The 3000 times of 20% Dinotefuran WG had the best control efficacy among all treatments on the 3rd day, its field control efficacy was 97.95%.The 4000 times of 10% Cyantraniliprole OD had the best control efficacy among all treatments on the 7th day, and the field control efficacy was 98.86%.The control efficacies of the two insecticides remained above 85% 1~7 days post treatment.The pesticides used to control the Brassicogethes aeneus F. in production should be quick acting,effective and safe for bees based on the comprehensive analysis. 20% Dinotefuran WG or 10% Cyantraniliprole OD can be used at rapeseed squaring stage and 20% Chlorantraniliprole SC can be used at rapeseed flowering stage.