杨干象是杨树的毁灭性害虫,分布于承德等地。幼虫在韧皮部环绕树干蛀食,蛀道深入木质部及髓部,切断树木输导组织,轻者枝梢干枯、风折,重者整株死亡。为了更有效地防治杨干象,现将对 Yang dry like poplar devastating pests, distributed in Chengde and other places. Larvae in the phloem around the trunk eaten, tunnels into the xylem and medulla, cut off the organization of the trees, the light branch dry, wind-fold, heavy whole plant died. In order to prevent and cure Yang dry as effectively, now will be right