Abstract: Clostera rufa is widely distributed in Yunnan Province.It is a serious pest of willow and poplar,especially of Salix heromera H=D and Poplus yunannensis Dade.There are two generations a year,winter is passed as lavae in the rolled leaves.In early spring the larvae feed on the bark of the host trees during the shortage of leaves. The bionomics of the pest is given. Experimental results that the insectides Sevin,Phoxim and Pipter were effective and that Sevim had a residual effectiveness of more than ten days.