几年来作者对螟虫越冬习性与防治的关系,作了一些调查和试验,现将所得结果汇报如下,以供参考。一、螟虫越冬态别、龄期几年来调查的结果证明:三化螟能以2—5龄幼虫越冬。能结茧的5龄幼虫才为较安全越冬幼虫,其余各龄幼虫均为无效过冬幼虫。二化螟以2—5龄幼虫过冬。大螟以2龄以上幼虫过冬,少数以蛹过冬。蛹在冬 In recent years, the authors made some investigations and experiments on the relationship between stem borers’ habit of overwintering and their prevention and control. The results obtained are reported below for reference. First, the stem borers do not win over the age of several years to investigate the results show that: Borer borer to 2-5 instar larvae wintering. The 5th instar larvae that can cocoon were the safe wintering larvae, while the rest larvae of all ages were ineffective overwintering larvae. Chilo suppressalis overwinters with 2-5 instar larvae. Sesamia in the second instar larvae over winter, a few overwintering pupae. Pupa in winter