甘蓝夜蛾(Mamestra brassicae)是河套地区甜菜主要害虫之一,80年代以来,每年都有发生,常对甜菜造成一定危害。据1982年至1984年的系统调查,甘蓝夜蛾在河套地区一年发生两代,以蛹在土层5～15cm处越冬,翌年5月初成虫始见,5月中下旬进入盛期。一代幼虫6月初始见,6月中下旬进入盛期。一代成虫7月上中旬始见,8月 Mamestra brassicae is one of the major beetles in the Hetao area. Since the 1980s, Mamestra brassicae has been on a yearly basis, often causing some damage to sugar beet. According to the systematic investigation from 1982 to 1984, the cabbage budworm occurred in Hetao area for two generations a year, pupal in the soil layer 5 ~ 15cm at the winter, early May the following year the adults began to see, in mid to late into the peak. The first generation of larvae saw the beginning of June, mid-to-late June into the peak. A generation of adults first seen in mid-July, August