甜菜夜蛾、甘蓝夜蛾、斜纹夜蛾是近几年北方秋十字花科蔬菜发生为害较严重的夜蛾科害虫,特别是１９９７、１９９９年为害猖獗。初孵幼虫群集在叶背,取食叶肉,残留表皮,３龄后可将叶片吃成孔洞或缺刻,严重时仅剩叶脉和叶柄,４龄后分散为害,昼伏夜出,进入暴食期钻入叶球为害,排泄 Beet armyworm, cabbage budworm and Spodoptera litura are pests of noctuid instar that have been severely damaged by the autumn autumn cruciferous vegetables in North China, especially in 1997 and 1999. The newly hatched larvae cluster on the leaf back, feeding on the leaves, leaving the epidermis, 3 years after the leaves can be eaten into holes or nicks, leaves and petioles in severe cases, scattered after the age of 4, nocturnal, into gluttonous drill Into the ball damage, excretion