三、青杨天牛(山杨天牛)又名杨枝天牛。分布于辽宁、吉林、黑龙江、河北、河南、青海、新疆和内蒙古等地区。为害多种杨树及蒿柳和朝鲜垂柳等。主要是幼虫为害枝干,特别是枝梢部分。幼虫先从韧皮部和木质部之间蛀道,稍长后蛀入木质部为害,从而阻碍养分的正常运输,并在被害处形成线穗形虫 Third, Green Yang Tian cattle (aspen), also known as Yang Zhi Tian Niu. Distributed in Liaoning, Jilin, Heilongjiang, Hebei, Henan, Qinghai, Xinjiang and Inner Mongolia and other regions. Damage to a variety of poplar and willow and North Korea weeping willows. Mainly larvae damage branches, especially shoots. The larvae first tunnel between the phloem and the xylem, after a long and later decay into xylem damage, thus impeding the normal transport of nutrients, and the formation of the line at the victim of beetles