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垂柳,是我国园林绿化的传统树种。然而近几年,张家口地区垂柳苗的病虫害非常严重,苗圃中树干通直而无病疤,生长健壮的优质垂柳大苗非常少见。经调查发现,危害垂柳的主要是吉丁虫、草履蚧、烂皮病。一、吉丁虫。俗称串皮虫。其幼虫在枝干皮层内蛀食,造成皮层干裂枯死,凹陷就成黑褐色,虫疤上常有红褐色粘液渗出。在张家口地区每年发生一代,以低龄幼虫在枝干皮层中越冬。翌春4月,幼虫继续在皮层内串食为害,5月中旬至6月上旬是严重危害
Weeping willow, is the traditional tree species of our country landscaping. However, in recent years, weeping willow seedlings in Zhangjiakou area have very serious pests and diseases. Trunks in the nursery are straight but without disease scarring, and the growth of strong weeping willow seedlings is very rare. The survey found that the main weeping willows jejuni, Carassius auratus, rotten skin disease. First, Jilin bug. Commonly known as Tandem insects. The larvae in the branches of the skin dry eclipse, resulting in cortical dry and dead, the depression becomes dark brown, insect scar often red brown mucus exudation. A generation occurs each year in Zhangjiakou area, with young larvae overwintering in branches and cortex. The next spring in April, the larvae continue to eat in the cortex harm, mid May to early June is a serious hazard