近年营造的杨树丰产林的特点是选用水肥条件好的立地,利用良种壮苗、密植、施肥和灌水,实行农林间作,使用配套的林业技术,在短轮伐期内获得高产。杨树生长迅速,枝繁叶茂,形成食料丰富和稳定隐蔽的害虫适生环境。随林龄的增加食叶害虫大发生频率增大,危害加重,近年丰产林中的膜肩网蝽每隔2—3年猖獗一次。1987年沂河林场的丰产林伴 Poplar trees in recent years to create a feature is the selection of good water and fertilizer site, the use of seedling strong seedlings, close planting, fertilization and irrigation, the implementation of intercropping with forestry, the use of supporting forestry technology, to obtain high yields in the short rotation. Poplar grow rapidly, flourish, the formation of food-rich and stable hidden pests habitat environment. With the increase of forest age, the frequency of occurrence of leaf-eating pests increases and the harm is aggravated. In recent years, the membrane shoulder-shoulder bug in high-yield forests is rampant once every 2-3 years. In 1987 Yihe Forest Farm with high yield