Extensive human-mediated jump dispersal within and across the native and
introduced ranges of the invasive termite Reticulitermes flavipes
Abstract
As native ranges are often geographically structured, invasive species
originating from a single source population only carry a fraction of the
genetic diversity present in their native range. This invasion pathway
is thus often associated with a drastic loss of genetic diversity
resulting from a founder event. However, the fraction of diversity
brought to the invasive range may vary under different invasion
histories, increasing with the size of the propagule, the number of
re-introduction events, and/or the total genetic diversity represented
by the various source populations in a multiple-introduction scenario.
In this study, we generated a SNP dataset for the invasive termite
Reticulitermes flavipes from 23 native populations in the eastern United
States and six introduced populations throughout the world. Using
population genetic analyses and approximate Bayesian computation (ABC),
we investigated its worldwide invasion history. We found a complex
invasion pathway with multiple events out of the native range and
bridgehead introductions from the introduced population in France. Our
data suggest that extensive long-distance jump dispersal appears common
in both the native and introduced ranges of this species, likely through
human transportation. Overall, our results show that similar to multiple
introduction events into the invasive range, admixture in the native
range prior to invasion can potentially favor invasion success by
increasing the genetic diversity that is later transferred to the
introduced range.