The impact of European urbanisation on moths and butterflies
Urbanisation puts modern pressures on ecosystems and the living things within them. New research has looked at the impact on two species of Lepidoptera – the Small Heath butterfly, Coenonympha pamphilus, and the Latticed Heath moth, Chiasmia clathrata. The work showed that in trying to understand the effects of the changing cityscape on insect life, we need to not only consider the modern environment in which species find themselves, but the pre-urban populations and their effect on the next generation.
The research used the population genomics of these two European grassland Lepidopterans and found that they have contrasting population structures. This suggests that urban populations probably emerged multiple times, highlighting the importance of historical and large-scale population dynamics in shaping urban evolution.
Strong differentiation in the Small Heath points to repeated independent urban origins, while high gene flow in the Latticed Heath indicates that connectivity and dispersal can blur the genetic boundaries between urban and rural populations. In other words, urbanisation does not drive evolution in a single, predictable way. The evolutionary impact of cities depends strongly on the population history and connectivity of the species.
The findings suggest that conservation in areas undergoing urbanisation need to work at the species level. Genetically structured species like the Small Heath may require protection of multiple, locally adapted urban and rural populations, while highly connected species like the Latticed Heath depend more on maintaining landscape connectivity and dispersal corridors to preserve genetic diversity and evolutionary potential.