Special thanks to A. Townsend Peterson for providing comments. Erin Saupe and Abby Morrison improved the English of an early version.The authors would like to thank the three anonymous reviewers for their voluntary suggestions and constructive critics that improved this manu script. LEE's research was supported by the Global Emerging
Infectious Disease Surveillance and Response System (GEIS) grant P0435_14_UN to Mark E. Polhemus. HQ was supported by the National Natural Sciences Foundation of China (grant 31100390).