The find of six species new to Belgium highlights the role of the stone trade as a pathway for non-native land snails (Gastropoda: Stylommatophora

Abstract

Surveys in stone yards in Wallonia (southern Belgium) led to the find of six taxa of land snails being new to Belgium and one being new to Wallonia. The new taxa can be divided into two groups: living animals of the European species Charpentieria itala, Laciniaria plicata, Chilostoma cingulatum, and Theba pisana, and shells with remains of the dead animals in the case of the Asian taxa Cathaica fasciola, Acusta sp., and Bradybaena jourdyi. The latter are widespread in their respective Asian native range while Acusta sp. and B. jourdyi had never been reported from Europe. We discuss the role of stone yards as hubs for the dispersion of land snails. The individuals of the newly observed taxa may have arrived in several waves (with successive arrivals of stones) and may not reproduce in the stone yard. We explore the risks of settling. In this study, we provide evidence that the doorsnails C. itala and L. plicata have already settled elsewhere in Wallonia. Theba pisana, C. fasciola and Acusta sp. have the potential to behave as invasive