棕肾圆盾蚧防治指标研究

STUDIES ON THE CONTROL THRESHOLD OF THE SILK TREE SCALE (AONIDIELLA SOTETSU (Takahashi))

本文组建了棕肾圆盾蚧Ａｏｎｉｄｉｅｌａｓｏｔｅｔｓｕ（Ｔａｋａｈａｓｈｉ）虫口密度与新银合欢Ｌｅｕｃａｅｎａｇｌａｕｃａ（Ｌ．）Ｂｅｎｔｈ枯枝率、枯枝率与木材损失率、林冠覆盖率分别与水土保持率间的一元回归模型、林冠覆盖率及年平均降雨量分别与水土保持量间的二元回归模型，确定了林冠覆盖率和水土保持量临界值以及木材年生长量、等于防治成本的水土损失以及木材损失和相应允许的林冠覆盖率损失，在此基础上，以改进的经济阈值模型：Ｃ＝∑ｎｉ＝１∑ｋｊ＝１（ＰｉＲｊ）·Ｄ·Ｆ，求出７０％、８０％及９０％林冠覆盖率下该虫的防治指标分别为：２．５９、１５．０２、２７．４４头／ｃｍ２。

In this paper,the simple linear regression relations between population density of Aonidiella sotetsu (Takahashi) and percentage of withered stick and between percentage of withered stick and damage percentage of trunk firewood, multiple regression relation among covering percentage of crown canopy and annual precipitation and water conservation, multiple regression relation among covering percentage of crown canopy and annual precipitation and soil conservation,simple linear regression relation between covering percentage of crown canopy and water conservation percentage,simple linear regression relation between covering percentage of crown canopy and conservation percentage,critical data of water and soil conservation ,critical percentage of crown canopy covering,damage percentage of water and soil conservation,damage percentage of crown canopy covering percentage and trunk firewood were studied.The results showed that the control threshold were 2.59,15.02 and 27.44 head scale/cm2,and at the same time the crown canopy coverings 70%,80% and 90% respectively.