榕片圆蚧树冠分布及抽样技术研究

A STUDY ON CROWN CANEPY SPATIAL DISTRIBUTION PATTERN AND SAMPLING TECHNIQUE OF AONIDIELLA SOTETSU TAKAHASHI

榕片圆蚧在新银合欢树冠的分布为负二项分布；林间取样方式以折线式最佳，取样枝部位以树冠南上部最具代表性；抽样数量公式为Ｎ＝２７．６／ｘ＋１８．３，序贯抽样公式按２．５９，１５．０２，２７．４４头／ｃｍ２的防治指标分别为Ｔ０（Ｎ）＝２．５９Ｎ±５．５５９３Ｎ，Ｔ０（Ｎ）＝１５．０２Ｎ±２７．０８９７Ｎ，Ｔ０（Ｎ）＝２７．４４Ｎ±４８．５０８９Ｎ．

In this paper,the crown canopy spatial destribution pattern and sampling technique of Aonidiella sotetsu Takahashi were studied. The results are shown as follows. The spatial distribution pattern of the pest in crown canopy is conformed with negative binomial distribution. The best method of collecting specimen is the broken-line one. The best place of collecting specimen is in the upper southern part of the crown canopy. The sampling number is calculated as the following model:N=27.6/+18.3. The models of sequential sampling are T0(N)=2.59N±5.5593N,T0([WTBX]N)=15.02N±27.0897N and T0(N)=27.44N±48.5089N which belong to 70%,80% and 90% crown canopy. 