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. |