Abstract: Rhyacionia leptotubula is a major destructive insect pest to Pinus armandii and P.yunnanensis,which damages the shoots of the pine trees.Distribution,hamfulness and biological characters of the insect pest were surveyed within Zhaoyang District,Yunnan Province.It was showed by the survey that this insect has only one generation each year in Dashanbao Township of Zhaoyang District,and overwinters by larvae inside the infested shoots.The overwintered larvae resume developing from mid March.Pupae period lasts from early April to early June.Adults emerge from mid May and the main oviposition phase is from early to mid June.The larvae begin to overwinter from early October.