Correspondence
∗Junbao Wen, Beijing Key Laboratory of Forest Pest Control, College of Forestry, Beijing Forestry University, P.O. Box 113, 35 Qinghua East Road, Haidian District, Beijing 100083, P. R. China. Tel: +86-10-62336842; Fax: +86-10-62336842; E-mail: wenjb@bjfu.edu.cn.
∗Ruihe Gao, Department of Forest Conservation, College of Forestry, Shanxi Agricultural University, 1st Mingxian Road, Taigu District, Jinzhong, Shanxi Province, P. R. China. Tel: +86-354-6285109; Fax: +86-354-6285109; E-mail: gaoruihe1989@163.com.