I work on population genetic structure of forest insects at different spatial scales, to look for processes limiting gene flow and to characterize and analyze hybrid zones (between species), or introgression (between lineages and populations). I use the tools of phylogeography and population genetics and genomics, especially on a species that is expanding following global warming, the pine processionary moth. I am also interested in changes in biological cycles and their consequences on evolutionary processes, focusing on a well-documented case of allochronic differentiation.