Niche modelling and landscape genetics of the yellow-legged hornet (Vespa velutina): An integrative approach for evaluating central–marginal population dynamics in Europe
Genetic diversity is an important biological trait for a successful invasion. During
the expansion across a new territory, an invasive species may face unprecedented
ecological conditions that will determine its demography and genetic diversity. The
first record of the yellow-legged
hornet (Vespa velutina) in Europe dates back to
2004 in France, from where it has successfully spread through a large territory in
the continent, including Italy, Spain and Portugal. Integrative approaches offer a
powerful strategy to detect and understand patterns of genetic variation in central
and marginal populations. Here, we have analysed the relationship between genetic
diversity parameters inferred from 15 V. velutina nuclear DNA microsatellite
loci, and geographical and environmental drivers, such as the distance to the introduction
focus, environmental suitability and distance to native and invasive niche
centroids. Our results revealed a central–marginal dynamic, where allelic richness
decreased towards the edge of the expansion range. The low environmental suitability
of the territories invaded by marginal populations could prevent a diverse
population from establishing and reducing the genetic diversity in populations at
the expansion edge. Moreover, Markov chain Monte Carlo analysis showed both
geographical and environmental distances were influencing population genetic differentiation.
This study highlights the importance of combining genetic analysis
with geographical and environmental drivers to understand genetic trends of invasive
species to new environment.
