Based on the recording and analysis of data collected in all regions of our continent, from North Cape to Crete, this work  has expanded our knowledge of insects. The southern European regions have a greater diversity than the northern ones and therefore represent the reservoir for the biodiversity of these insects. During the glaciations, central and northern Europe was covered by ice and the life of the butterflies was impossible. At the end of the glaciations, the butterflies were able to colonize the northern regions. But not all the genetic wealth accumulated in southern Europe has migrated to the north, only that small part belonging to the individuals that, casually, have moved towards the new areas made available by the retreat of the ice. This phenomenon, described as 'southern richness and northern purity' and verified thanks to our research  tells us that in Southern Europe biodiversity, fundamental for the adaptation and survival of butterflies, is higher.