大叶黄杨是目前我国北方地区城市园林绿化、改善生态环境的优良常绿阔叶树种,其枝叶浓密,嫩叶绿色有光泽,四季常青,且有各种花叶变种。因此,有较高的观赏价值。近几年来,由于在地域间的苗木交流中忽视了对病虫害的检疫及处理,加上苗木基地的单一品种多年连茬种植,且种植密度逐渐增加,使得病虫害发生面积逐年扩大,一些病虫害由于防治不 Euonymus japonicus is an excellent evergreen broad-leaved tree species in urban landscaping and ecological environment improvement in northern China. Its leaves are dense, green leaves are lustrous, evergreen, and all kinds of mosaic varieties. Therefore, there is a higher ornamental value. In recent years, due to the inter-regional exchange of seedlings neglected the quarantine and treatment of pests and diseases, coupled with a single seedling base for many years continuous planting, and planting density gradually increased, making the area of ​​pests and diseases increased year by year, some pests and diseases because of prevention and treatment Do not