采用大田笼罩接虫法观察研究南美斑潜蝇危害菜豆经济损失结果表明,豆株上虫量越大,被害指数越高,经济损失就越大。单株虫量在0.75,1.25,2.5,3.75,5.0,6.25,7.5,8.75,10 头时,造成的产量损失率分别是7.76% ,13.89% ,24.82% ,28.73% ,33.22% ,33.7% , 34.07% ,50.38% ,57.22% ,经济损失率分别为13.53% ,19.28% , 31.87% , 35.4% , 40.31% , 41.99% ,42.31% ,57.82% ,64.06% 。受害叶指数分别为0,6.6,10.4,11.8,14.4,18.0,21.3,26.6,41.9,54.8。根据经济阈值,确定南美斑潜蝇防治指标成虫为18～25 头/百株。 The results showed that the larger the pests on pests and the higher the index of pests, the greater the economic loss. When the number of single plant worms was 0.75,1.25,2.5,3.75,5.0,6.25,7.5,8.75 and 10 heads, the yield loss rates were 7.76%, 13.89%, 24.82%, 28.73%, 33.22% and 33.7% respectively, 34.07%, 50.38% and 57.22% respectively. The economic loss rates are 13.53%, 19.28%, 31.87%, 35.4%, 40.31%, 41.99%, 42.31%, 57.82% and 64.06% respectively. Viciae leaf index were 0,6.6,10.4,11.8,14.4,18.0,21.3,26.6,41.9,54.8. According to the economic threshold, adult adults with control index of Liriomyza sativae were 18-25 heads per 100 plants.