论文部分内容阅读
一字竹象虫(Otidognalhus davidis)在我省主要危害桂竹(Phyllostachys bomb-usoides),故通称桂竹象鼻虫。镇扬山区和太湖地区的桂竹被害率达95%以上,被害竹材质僵硬、烂头断梢,因此群众称桂竹为“烂头桂”,为害之重,可以想见。此虫在本省一年发生一代,以成虫在林地下8—20厘米深处土室内越冬,翌年五月下旬出土,成虫用管状喙刺入竹笋啮食作为补充营养,然后交尾,产卵于笋内,卵期3—5天。幼虫孵化后即在原产卵穴内吃食笋肉,幼虫共五龄,三龄后幼虫食量增大,一般不转移,仍在原处取食,故使笋被咬食面积较大,风吹后,易断头拆梢。幼虫期15—20天,6月中、下旬,老熟幼虫陆续咬破笋箨入土筑土室化蛹,蛹期10—20天,7月下旬成虫羽化后,即在原土室内越夏、越冬。
Otidognalhus davidis is a major threat to Phyllostachys bomb-usoides in our province, so it is known as the weevil. The town of Yangshan and Taihu Lake area of ?? more than 95% of the victims of calamus, bamboo victim to the rigid material, broken head, so the people called the “bamboo shoots Guizhu”, the weight of harm can be imagined. This pest occurs in the province one year a generation to adults in the forest floor 8-20 cm deep soil inside the winter, unearthed in late May the following year, adults with tubular beak pierced into the bamboo shoots serve as supplementary nutrition, and then copulate, spawning in shoots Within 3-5 days of oviposit period. The larvae hatch in the spawning in the spawning after eating raw bamboo shoots, larvae a total of five years old, three instar larvae food intake increases, the general does not transfer, still in place to eat, so the bamboo shoots are biting area, the wind, easy Broken broken tip. Larvae 15-20 days, mid-to-late June, mature larvae bite one after another bamboo shoots into soil earthwork pupation, pupal period 10-20 days, after the emergence of adults in late July, that is, in the original soil summer, wintering.