基金
Acknowledgements We thank X Wang, Y Xiao, G Chen and D Huang for helps with trapping and seed collection. Z Zhang provided comments on an earlier version of this manuscript. We also thank the four anonymous reviewers for critical comments and suggestions. This study was partially funded by the Knowledge Innovation Program of the Chinese Academy of Science （KSCX2-SW-105, KSCX2-SW-103） and the National Natural Science Foundation of China （30800120）.
