摘要
通过聚集度指标的计算分析 ,明确了黄刺蛾 [Cnidocampa f lavescens(Walker) ]越冬茧呈聚集型的一般负二项分布。用 Iwao方法给出了抽样技术 ,理论抽样数量当 t=1 .0 D =0 .3时 ,n =1 3 .46/x+5 .3 4。如果防治指标定为每株 1 .5个越冬茧时 ,序贯抽样的累积越冬茧数量界限为 :Tn =1 .5 n± 3 .3 3 67n ,聚集原因由于环境因素引起。
Based on analysis on index of gathering, Cnidocampa flavescens (Walker) hibernating cocoon is defined to be in negative binominal distribution. Sampling technique is given by use of Iwao method. The theoretical sampling quantity is when t=1.0 and D=0.3, n=13.46/+5.34. If the index of prevention and combat is determined as 1.5 hibernating cocoon for each tree, the limits of quantity of accumulated hibernating cocoon for sequential sampling is Tn=1.5n±3.3367n. The gathering is caused by environment factor. The sequential sampling technique and determination of sampling quantity are statistic indexes which are able to reference in prevention and combat.
出处
《内蒙古林业科技》
2001年第4期24-26,共3页
Journal of Inner Mongolia Forestry Science and Technology
关键词
黄刺蛾
越冬茧
空间分布
抽样技术
黄刺蛾
森林虫害
Cnidocampa flavescens (Walker)
hibernating cocoon
spatial distribution
sampling technique
