Genetic origin and dispersal of the invasive soybean aphid inferred from population genetic analysis and approximate Bayesian computation.

Biological invasion is considered among the most important global environmental problems. Knowledge of the source and dispersal routes of invasion could facilitate the eradication and control of invasive species. Soybean aphid, Aphis glycines, is among the most destructive soybean pests. For effective management of this pest, we conducted genetic analyses and approximate Bayesian computation analysis to determine the origins and dispersal of the aphid species, as well as the source of its invasion in the USA, using 8 microsatellite loci and the mitochondrial cytochrome c oxidase subunit I gene. We were able to identify a significant isolation by distance pattern and 3 genetic lineages in the microsatellite data but not in the mtDNA dataset. The genetic structure showed that the USA population had the closest relationship with those from Korea and Japan, indicating that the 2 latter populations might be the sources of the invasion to the USA. Both population genetic analyses and approximate Bayesian computation showed that the northeastern populations in China were the possible sources of the further spread of A. glycines to Indonesia. The dispersal history of this aphid can provide useful information for pest management strategies and can further help predict areas at risk of invasion.