在中卫县四旁及成片的杨树上,杨笠圆盾蚧被害木占80％左右,严重影响树木生长成材,威胁农田林网化建设。我们自1979～1984年对其生活史作了观察,并作了各种药剂防治试验,简结如下: 一、分布及危害该虫在东北、新疆、内蒙及我区均有分布在我县主要危害箭杆杨、合作杨、群众杨、大观杨、 On the four sides of Zhongwei County and the poplar trees, the Yangliu saxifrage trees account for about 80% of the damaged trees, seriously affecting the growth of trees and threatening the construction of farmland network. We observed their life history from 1979 to 1984 and made various kinds of chemical control experiments. The brief summary is as follows: I. Distribution and Harms The insect is mainly distributed in the northeast, Xinjiang, Inner Mongolia and our district Danger Arrow Yang, Yang cooperation, the masses of Yang, Grand View Yang,