杉木球果麦蛾种群动态规律的研究

杉木球果麦蛾是杉木的主要种实害虫，其危害可造成种子品质和产量的严重下降。据４个年份的调查结果表明，杉木球果麦蛾幼虫种群数量变动比较稳定。每样枝平均虫口密度在０．２５─２．５条内变动。因幼虫在球果内栖息和危害受外界气候、天敌等影响小，故存活率较高：根据４年的观察比较，平均存活率８５．８％。可以此作为参数，准确预报翌年的种群消长趋势，为生产上开展综合治理提供科学依据。

Studies on the Population Dynamics Law of Dichomoris bimaculatus

The four－year survey results show that the larVal population quantity change of Dichomoris bimac-ulatus is relatively stable and the average survival rate is 85．8％. We may take this rate as a parameter to ac-curately forecast the population growth and decline tendency next year for providing a scientific basis for thedeveloprnent of comprehensive harnessing in production.