随着植树造林事业的迅速发展,杨树人工林面积逐年扩大,各种食叶害虫的危害也日趋严重。长期以来,出于不了解树木对害虫危害的耐受能力及何种虫口密度能造成树木生长量减少,没有定量性的科学系统的估计指标,致使防治工作的决策缺乏科学依据,盲目性很大,且往往造成人、财、物的极大浪费。为了科学、经济、有效地控制森林害虫的危害,由吉林省林业厅下达和组织,白城地区森林病虫防治检疫站主持,长岭和梨树县森防检疫站参加,进行了“杨树五种食叶害虫危害指标”的 With the rapid development of afforestation, poplar plantation area has expanded each year, the dangers of various leaf-eating pests have become increasingly serious. For a long time, people who do not understand the tolerance of trees to pests and what kind of insect population density can reduce the growth of trees, there is no quantitative indicators of the scientific system, resulting in a lack of scientific basis for decision-making prevention and control work, blindness , And often caused great waste of people, money and things. In order to scientifically, economically and effectively control the harm of forest pests, Jilin Provincial Forestry Bureau issued and organized the forest pest control quarantine station in Baicheng area, and Changling and Lishu County Forest Prevention and Quarantine stations participated in the “ Leaf insect pests hazard index ”