Abstract: The Deileptenia sp. is an important pest of the pinus armandii (Franch). The larvae damage the pinus armandii (Franch) and feeding on the needle from the middle part to the basic part. The heavy harmed forest looke like the burned trees. There is one geneiation a year in Kunming, and hibernates in the form of pupae undei the humus soil. The pupae emerge from May to July of the next year. The peak of eclosion-rate is in the middle ten days or the last ten days of June. The adult has strong phbtotaxis and chemiotaxis. The adult can be trapped and killed in the adult stage by using black light or fiesh excrement of oxen and horses. And using pyrethroid and smoke to control larvae in larval stage can gain a remarkable effect.