Contrasting genetic responses to habitat fragmentation for two Lycaenid butterfly species

Biodiversity is currently declining at the global scale. Apart from
species declines and lowered abundances, the loss of genetic diversity is
equally concerning as it may undermine fitness and the potential to adapt
to future environmental change. We compared genetic diversity of
historical and recent Alpine populations of two butterfly species, Lycaena
helle and L. hippothoe, over a period of about 10 years. Using
microsatellite markers, we found no changes over time in L. helle, while
genetic diversity decreased, and differentiation increased in L.
hippothoe. Lycaena helle inhabits peat bogs and wetland fallows with
populations being strongly isolated, while L. hippothoe used to occur in
population networks on hay meadows, with the latter being strongly exposed
to agricultural intensification. We conclude that currently L. hippothoe
populations are strongly declining due to changes in land use, resulting
in genetic erosion potentially due to the collapse of population networks.