几种杀虫剂对菜蚜和小菜蛾的防治效果及应用技术研究

菜蚜防治试验结果表明,60%吡蚜酮和70%吡蚜酮WG对甘蓝蚜虫具有良好的防治效果,用药后3～10 d的防效明显优于对照农药2.5%高效氯氟氰菊酯EW;与对照农药3%啶虫脒EC和10%吡虫啉WP相当;持效期长,是防治甘蓝蚜虫的理想药剂,推荐有效使用剂量分别为81～117,84～126 g/hm2,在菜蚜发生初盛期及时喷雾施药。小菜蛾防治试验结果表明,氯虫苯甲酰胺、茚虫威和氟虫双酰胺对小菜蛾具有良好的防治效果,用药后2,5 d的防效分别达到85%和90%以上,用药后7 d仍维持在90%左右,与对照农药1.8%阿维菌素EC的防效相当。建议在生产上使用200 g/L氯虫苯甲酰胺SC,150 g/L茚虫威EC和20%氟虫双酰胺WG防治甘蓝小菜蛾,有效使用剂量分别以30～37.5,33.75～40.5,30～45 g/hm2为宜,在小菜蛾低龄幼虫初盛期及时喷雾防治。

Control Efficacy and Application Technique of Five Insecticides against Aphid and Diamondback Moth in Cabbage Field

The efficacy of five new insecticides was determined against aphid and diamondback moth in cabbage field.Results indicated that pymetrozine 60% and 70% WG provided excellent control of aphid.Efficacy ranged between 96.0%～99.6% from 3 to 10 days after spraying treatment,and it lasted for more than 10 days,which were significantly better than that by applying lambda-cyhalothrin 2.5% EW at 6.56 g/hm2 and similar to that by using acetamiprid 3% EC at 15 g/hm2 or imidacloprid 10 % WP at 15 g/hm2.It was suggested that the application rate against aphid was 81～117 g/hm2 for pymetrozine 60% WG and 84～126 g/hm2 for pymetrozine 70% WG.Spraying should be made when aphid numbers were at the beginning to rise.Results also showed that chlorantraniliprole,indoxacarb and flubendiamide revealed to be effective on diamondback moth.Reduction percentage of the larvae was more than 85% and 90% at 2 and 5 days after spray treatment,respectively,and remained about 90% at 7 days after the spray,which was equivalent to that by using abamectin 1.8% EC at 10.8 g/hm2.It was recommended that the application rate against diamondback moth was 30～37.5 g/hm2 for chlorantraniliprole 200 g/L SC,33.75～40.5 g/hm2 for indoxacarb 150 g/L EC and 30～45 g/hm2 for flubendiamide 20% WG.Spraying should be applied just when most of the population is in the small nymph stage of development.