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采用聚集指数ｂ值测定，扩散系数（Ｃ）测定，Ｉｗａｏ法测定以及Ｄａｖｉｄ和Ｍｏｏｒｓ聚集指标Ｉ测定４种方法来研究杉木扁长蝽若虫的空间分布型和最适抽样数，结果表明：在不同林地、不同虫口密度情况下，均呈聚集分布。若虫聚集是环境所致。
The spatial distribution patterns and the optimal sampling numbers of Cnidium elongatus nymphs were studied by means of aggregation index b value determination, diffusion coefficient (C) determination, Iwao method determination and David and Moors aggregation index I determination. The results showed that in different Woodland, different population density of insects, were aggregated distribution. Nymph aggregation is caused by the environment.