小菜蛾Plutella xylostella(Linnaeus)属鳞翅目菜蛾科,又名菜蛆、小青虫、扭腰虫、吊死鬼等。它分布很广为世界性种类,我国各省、市、自治区均有记载;西藏从低海拔农区到海拔4000多米的高寒农区,都有它的分布。主要危害十字花科蔬菜,甘兰、白菜、萝卜等,在区又是油菜上的重要害虫之一,易贡农场的一块油菜地,曾因幼苗期遭受小菜蛾的严重危害而毁种。 Plutella xylostella (Linnaeus) is a member of the family Lepidoptera, also known as vegetable maggots, larvae, tussocks and hanged ghosts. It is widely distributed in a worldwide category, and is recorded in various provinces, municipalities and autonomous regions in China. Tibet has its distribution from a low altitude agricultural area to an alpine farming area at an altitude of over 4,000 meters. Major hazards cruciferous vegetables, cabbage, cabbage, radish, etc., in the area is one of the major pests on rape, a rape farm in Yi Gong farm, once severely threatened by the diamondback moth during seedling stage.