小菜蛾 Plutella xylostella L.是世界性的蔬菜害虫之一。主要危害甘兰、大白菜、小白菜、油菜等十字花科蔬菜作物达三十九种。七十年代以来,由于小菜蛾抗药性增强,漫延全国各地,尤以长江流域各省危害最为严重。在武汉自然条件下终年繁殖十三代,世代重叠,连续危害,对蔬菜生产造成相当严重的损失。如武昌洪山公社井岗山大队1976年 Plutella xylostella L. is one of the world’s vegetable pests. The main endanger cabbage, cabbage, cabbage, rape and other cruciferous vegetables up to thirty-nine kinds of crops. Since the 1970s, due to the increased resistance to diamondback moth, it has spread all over the country, especially the provinces in the Yangtze River valley. In the natural conditions of Wuhan year-round breeding thirteen generations, generational overlap, continuous harm, causing serious losses in vegetable production. For example, Wuchang Hongshan Commune Jinggangshan brigade in 1976