粗鞘双条杉天牛(Semanotus bifaeiatus sinoauster Gressitt)~(**)是我国南方杉木纯林中的毁灭性害虫。据调查10年生的杉木纯林一般危害株率达60％,断鞘枯死率达20—30％。关于对杉天牛的生活习性发生规律和防治办法,前人都做了大量的研究工作,总结了一套比较有效的防治方法,但由于杉树高大,面积太大,采用药物防治投工太多,生物防治成本太高,难于在生产中推广。我们于1980年至1981年分别在湖南汨罗县智丰混交林区和玉池人工纯林区设立了观测点,探测了森林生态环境的变异及林型的组成对杉天牛发生与生态环境关系的研究。现将结果报道如下: Semanotus bifaeiatus sinoauster Gressitt ~ (**) is a devastating pest in the pure Chinese fir plantation in southern China. According to a survey of 10-year-old Chinese fir pure plant damage rate of 60% of the general, broken sheath dead rate of 20-30%. On the crab crab life habits and control measures, predecessors have done a lot of research work, summed up a set of more effective control methods, but the cedar tall, too large, too much use of drug control , Biological control costs are too high, difficult to promote in production. In 1980-1981, we set up observation points in Zhichuang mixed forest area and Zhuchi artificial pure forest area in Miluo County, Hunan Province, respectively, and explored the variation of forest ecological environment and the composition of forest types on the occurrence and ecological environment of Cunninghamia lanceolata the study. The results are reported as follows: