松突圆蚧空间分布型的研究

应用聚集度指标和回归分析，对松突圆蚧空间分布型进行测定，结果表明：松突圆蚧的若虫在松林中呈聚集分布，聚集度随虫口密度增大而增强；而成虫在松林中呈均匀分布，从而确定出不同种群密度下最适抽样数。通过林间调查和数理统计分析，结果表明：松突圆蚧在松树枝条的东、南、西、北不同方位，以及松树树冠的上、中、下不同层次和幼林、中龄林、成林不同树龄的松林之间的虫口数量差异不显；但在郁闭度不同的松林中虫口数量存在着显差异。

The spatial distribution pattern of Hemiberlesia pitysophila Takagi

Measured by cluster index and regressive analysis method,the spatial distribution pattern of Hemiberlesia pitysophila Takagi was studied. The results showed that in pine forest,the spatial distribution pattern of the nymphs are tested to aggregative distribution. However,the adults is tested to uniform distribution. The optimal sampling number for different population density was analyzed and calculated. Depending on the result of forest survey and mathematical analysis, it was also found that population density were not significantly different at various trees directions of East, South, West and North, and at different levels of upper, middle and lower, and also at different tree age of young, middle and old. However, in different density of plant cover, population density is tested to remarkable difference.