Abstract: This paper deals with the injuries caused by Tomicus piniperda to theshoots of Pinus yunnanensis in shoot-feeding period in Kunming region of China.Information on its biological characteristics including sex ratio, mating, feeding preference and habit, hibernating and ovary development is presented and discussed.The shootfeeding period in Kunming started during May and lasted to Marchthe next year, in which each beetle bored 3 to 6 shoots. Most damaged shootswere the current shoots with 7Drosophila (Drosophila)7～8.5mm diameter. The same shoot could bedamaged several times, but frequently two times. The entrance hole was about3～4 cm far from the shoot tip. Mating was observed during shootfeeding and the mating rate increased progressively with ovary development. The developmentduring the winter season slowed down due to low temperature. Successfulhibernation was observed for all stages.

Key words: Tomicus piniperda, biology, Pinus yunnanensis