摘要
本文运用聚集度指标法、回归模型法和频次分布法研究了马尾松毛虫越冬代幼虫的空间分布型.结果表明幼虫的分布型符合聚集分布.低密度情况下的幼虫服从Neyman A型分布,幼虫在单株树上的分布服从负二项分布,各轮枝层虫口密度差异显著,可将其划分为3组.比较6种不同的抽样方法,以Z字形法为最好,抽样数量以24株为宜.
The spatial distribution patterns of overwintering larvae of the pine caterpillar were studied by means of index of aggregation regression modle and frequency distribution. The result showed an aggregation distribution pattern for the larvae. Under low population density the distribution of the larvae obeyed Neyman distribution. In a single pine tree the larvae exhibited negative binomial distribution. The larval density between verticillate branches varied greatly and it should be divided into three groups. Different sampling methods were compared and the Z-shaped method found to be the best. The number of trees form which we took samples for survey was 24.
出处
《华南农业大学学报》
CAS
CSCD
1993年第4期89-94,共6页
Journal of South China Agricultural University
关键词
马尾松毛虫
空间分布型
抽样方法
Pine caterpillar
Spatial distribution pattern
Sampling method
