Population genetic structure of the predatory, social wasp Vespula pensylvanica in its native and invasive range

Invasive species cause extensive damage to their introduced ranges. Ocean archipelagos are particularly vulnerable to invasive taxa. In this study, we used polymorphic microsatellite markers to investigate the genetic structure of the social wasp Vespula pensylvanica in its native range of North America and its introduced range in the archipelago of Hawaii. Our goal was to gain a better understanding of the invasion dynamics of social species and the processes affecting biological invasions. We found that V. pensylvanica showed no significant genetic isolation by distance and little genetic structure over a span of 2000 km in its native range. This result suggests that V. pensylvanica can successfully disperse across large distances either through natural- or human-mediated mechanisms. In contrast to the genetic patterns observed in the native range, we found substantial genetic structure in the invasive V. pensylvanica range in Hawaii. The strong patterns of genetic differentiation within and between the Hawaiian Islands may reflect the effects of geographic barriers and invasion history on gene flow. We also found some evidence for gene flow between the different islands of Hawaii which was likely mediated through human activity. Overall, this study provides insight on how geographic barriers, invasion history, and human activity can shape population genetic structure of invasive species. We studied the invasion biology of a social wasp in Hawaii using genetic markers in order to understand how social species successfully invade new habitats. We found that the genetic structure of the wasp differed greatly between invasive and native populations. In addition, the genetic patterns provide insight into how this wasp successfully colonized the Hawaiian Islands. Overall, this research helps us understand how invasive social insects come to dominate new habitats.