1. Laboratory of Forestry Pests Biological Control, College of Forestry, Northwest A&F University, Yangling, Shaanxi, 712100, P. R China
2. These authors contributed equally to this work
3. College of Science, Northwest A&F University, Yangling, Shaanxi, 712100, P. R China
4. Wuwei Academy of Forestry Sciences, Wuwei, Gansu 733000, P.R. China