马尾松毛虫空间分布型及其在实践上的应用

Spatial Distribution Patterns of the Pine Caterpillar ( Dendrolimus Punctatus Walker ) and Its Application in Practice

本文运用频数分布法,聚集度指标法和相关系数法研究了马尾松毛虫(Dendrolimus punctatus Walker)卵、幼虫和蛹的空间分布型。结果表明,卵、小幼虫、大幼虫和蛹的分布型均属于负二项分布。五种抽样方法比较结果,棋盘式取样法最好。根据Iwao方法分析并计算了不同虫口密度下林间调查的最适取样数,进行了序贯抽样以及虫口密度与有虫株率关系的研究。

Spatial distribution patterns for egg-masses, small larvae, large larvae and pupae of the pine caterpillar were measured by the method of frequency distribution, means of several inde es of aggregation and corelation coefficient method in Fujian Province. Frequency distribution of the egg-masses,small larvae,large larvae and pupae obeyed aggregation distribution. The results of five sampling methods showed that the method of scattering proved to be ethe best.Based on Iwao's methods the optimal sam ling number of forest survey was analysed and calculated. The sequential analysis, the relationsnip between the percentage of plants with larvae or pupae and mean nopulation density were also studied.