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杨干象 Cryptorrhynchus lapathi Li-nne 属鞘翅目,象甲科。杨干象是杨、柳树的毁灭性害虫,也是我国重要的森林植物检疫对象,过去在我省未见公开报道。今春在我所实验苗圃杨、柳林内该虫严重发生,以幼虫在3年生以上的杨、柳树枝干韧皮部环绕树干蛀道为害,破坏输导组织,使植株因营养、水分受阻而树势衰弱,轻者造成枝干干枯,重者能使整株死亡,给林木生长发育造成很大的影响,严重威胁幼树成林。据我们调查,该虫在苗圃发生面积40余亩,其中有8亩沙兰杨为害严重,被害株率达88.5%,其中干枝枯梢的占49%,死亡的占19%,平均每株虫口密度4头,最高达34头。其余20
Cryptorrhynchus lapathi Li-nne is a Coleoptera, like a branch. Yang dry as Yang, willow devastating pests, but also China’s major forest plant quarantine object, in the past, no public coverage in our province. This spring in my experiment nursery Yang, Liulin serious occurrence of the worm, larvae in more than 3-year-old Yang, Willow branches phloem around the trunk tunnel damage, destruction of tissue conduction, so that plants due to nutrition, water resistance and tree weakness , The light causes branches to dry up, the heavier can make the whole plant to death, which has a great impact on the growth and development of trees and threatens the success of young trees. According to our investigation, the insects occurred in the nursery area of more than 40 acres, of which 8 acres of serious damage caused by Poplar, victimization rate of 88.5%, of which dry branches accounted for 49%, 19% of deaths, the average per plant Insect density of 4, up to 34 head. The remaining 20