Submitted to: Molecular Ecology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 9/20/2011
Publication Date: 12/19/2011
Publication URL: http://handle.nal.usda.gov/10113/55907
Citation: Yang, C., Ascunce, M.S., Luo, L., Shao, J., Shih, C., Shoemaker, D.D. 2011. Population genetics reveals multiple introductions and subsequent cross-province movements of the invasive fire ant Solenopsis invicta in China. Molecular Ecology. 21:817-833. Interpretive Summary: Fire ants are considered significant ecological, agricultural, and public health pest throughout their invasive range in the U.S.A. Scientists at the Center for Medical, Agricultural, and Veterinary Entomology, USDA-ARS, Gainesville, Florida and scientists from National Taiwan University and the Chinese Academy of Agricultural Sciences describe here the results of a study examining patterns of genetic variation and structure in the invasive fire ant populations in China. This study provides the most detailed and comprehensive population genetic study of fire ants in China and revealed several noteworthy patterns regarding the invasion history, likely routes of subsequent dispersal, and signatures of genetic bottlenecks of this pest ant species in China.
Technical Abstract: We characterized patterns of genetic variation in populations of the invasive fire ant Solenopsis invicta in China using both mitochondrial DNA sequences and nuclear DNA microsatellites. All study samples, which were collected from 17 sites across the current infested range in China, were assigned to one of three distinct genetic clusters, consistent with the hypothesis that there were at least three independent invasions of S. invicta into China. Most colonies from spatially distant, outlying areas are genetically similar to one another and appear to share a common source (Wuchuan, Guangdong province), suggesting that long-distance jump dispersal has been a prevalent means of recent spread of fire ants in China. Furthermore, most colonies at outlier sites are of the polygyne social form (featuring multiple egg-laying queens per nest), reinforcing the important role of this social form in subsequent range expansion following initial invasion. Several analyses reveal characteristic signatures of genetic bottlenecks for S. invicta populations in China. The major findings of this study (i.e., multiple introductions, long range dispersal, and genetic bottlenecks) are consistent with those of earlier investigations of other invasive fire ant populations.