Abstract: The Yunnan pine weevil, Pissodes yunnanensis Langor et Zhang, is an insect pest species discovered recently on the Yunnan pine, Pinus yunnanensis. It is mainly distributed in the central and northwestern Yunnan, and certain areas in Guizhou and Sichuan provinces. The weevil was univoltine. In Lijiang, northwestern 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 the terminal leaders and the upper lateral branches. After one year of the weevil infestation, the damaged terminal leaders or branches usually withered, and consecutive infestation of two or three years resulted in young pine death.

Key words: Pissodes yunnanensis, Pinus yunnanensis, life cycle, biology, instar