一、毛白杨皱叶病又称毛白杨瘿螨。陕西、甘肃、河南、河北、天津、北京等地均有发生。从幼树到大树均可受害,但主要为害5年生以上的毛白杨。1、症状叶片被害后皱缩变形,肿胀变厚,卷曲成团,呈紫红色,似鸡冠状,故名皱叶病。在一个芽中几乎所有叶片都受害,春季冬芽开始舒展后,即表现出病状。一般被害芽较健康芽展叶早,以后随着叶片的 First, white poplar leaf blight also known as white poplar scabies mites. Shaanxi, Gansu, Henan, Hebei, Tianjin, Beijing and other places have occurred. From young trees to trees can be victimized, but the main damage to more than 5-year-old white poplar. 1, symptoms Foliar deformation after injury, swelling, thickened, curly into a group, was purple, like chicken coronally, hence the name of red leaf disease. Almost all the leaves in a bud have been harmed and show signs of spring when winter buds start to stretch. Generally budding sprout health buds show leaf earlier, with the leaf later