Genetic structure and new breeding populations of the garden snail <i>Cornu aspersum</i> (O. F. Müller 1774) (Mollusca: Gastropoda: Pulmonata: Helicidae) in Central Europe

The garden snail Cornu aspersum is considered an invasive alien species worldwide. Despite its Mediterranean origin, its European distribution is mostly a result of man-mediated translocations. Its range is continuous in Western Europe, but Central Europe seems to be at the edge of the expansion, revealing a patchy distribution. This contribution shows new data on its distribution and genetic structure in Poland. We found two viable populations, one in northern and one in southern Poland. At both sites, juvenile individuals were present, and the southern population has persisted for several years. The genetic structure reveals relatively high divergence between localities, which suggests multiple introductions from different sources. There is no evidence that the species fulfils the invasive species definition in the studied region; however, urban heat islands in temperate areas may support source populations of this species in the future. The species may also benefit in Central Europe from climate warming.