云南木蠹象的生物学研究

云南木蠹象Pissodes yunnanensis Langor et Zhang是我国西南地区近年来发现的森林蛀干害虫。该虫在云南西北部的丽江地区一年发生一代。成虫于6月下旬开始产卵, 产卵部位为当年生或头年生枝梢。7月上旬幼虫开始孵化，幼虫有4个龄期。11月中旬后，幼虫开始在受害枝内越冬，次年2月中下旬恢复活动。3月下旬至5月上旬为蛹期，4月中旬开始羽化。该虫主要危害云南松幼树，常造成受害树长势下降和树干畸形，连续危害2～3年可导致树木干枯死亡。

Bionomics of the Yunnan pine weevil, Pissodes yunnanensis (Coleoptera:Curculionidae)

The Yunnan pine weevil, Pissodes yunnanensis Langor et Zhang, is an inse ct pest species discovered recently on the Yunnan pine, Pinus yunnanensis. I t is mainly distributed in the central and northwestern Yunnan, and certain area s in Guizhou and Sichuan provinces. The weevil was univoltine. In Lijiang, north western Yunnan, the adults emerged from mid-April to mid-July, and oviposited from late June to August. It had four larval instars, which infested the Yunnan pine from early July until the next March, and overwintered as grown-up larvae inside the pine stems. Pupae appeared in March. Oviposition occurred mostly in t he terminal leaders and the upper lateral branches. After one year of the weevil infestation, the damaged terminal leaders or branches usually withered, and con secutive infestation of two or three years resulted in young pine death.