Study of pest resistance on mixed forest to Tomicus piniperda

In the seriously damaged area of Tomicus piniperda in Yunnan Province,pest resistance to Tomicus piniperda of pure forest and different mixed forests was studied through surveying mixed forests of Pinus yunnanensis and Castanea mollissima,Keteleeria fortunei,Pinus armandii,Alnus nepalensis,Quercus acutissima which mixed by group,strips and single tress.The result showed that the pest resistance of mixed stand to Tomicus piniperda was stronger than pure stand.The insect resistance of mixed forests of Pinus yunnanensis and Castanea mollissima,Pinus armandii was better.The resistance of mixed by single tress was best,row mixed model was better,group mixture was bad.