美国白蛾主要为害果树、行道树和观赏树木等阔叶树及各种农作物,在我省为害100多种植物,这是一种世界检疫性害虫。美国白蛾以幼虫期为害植物。幼虫在1～4龄之前群居网幕内,5龄开始分散为害植物,到7龄时可以把树叶连同叶脉一起吃掉,仅留下主脉。一头幼虫一生可吃掉10～15片桑树叶片或糖槭树叶片,3～4天就可将受害树的叶于全部吃光。因此,在幼虫4龄前可利用高枝剪、剪枝钩把网幕剪掉,集中烧毁或深埋。 The United States mainly to damage the white moth fruit trees, road trees and ornamental trees and other broad-leaved trees and a variety of crops, in our province more than 100 kinds of plants, which is a world quarantine pests. American white moth larvae damage plants. The larvae clustered in the screens before the age of 1 to 4, and the plants started to disperse in the fifth instar. By the seventh instar, the leaves could be eaten together with the veins, leaving only the main veins. A larvae can eat 10 to 15 pieces of mulberry leaves or sugar maple leaves throughout their lives, 3 to 4 days to eat all the leaves of the victim tree. Therefore, 4 years before the larvae can use high branches, cut the hook to screen cut off, concentrated burned or buried.