Etruscodytes nethuns n. gen., n. sp.: the first phreatic water beetle from Italy (Coleoptera: Dytiscidae: Hydroporinae)

Etruscodytes nethuns, new genus and species of subterranean water beetle, is described from Italy. This phreatic beetle was collected pumping water from a well in Tuscany (Central Italy). It is the third genus of stygobiontic dytiscid beetle from Europe and the first record of a stygobiontic water beetle in Italy. Etruscodytes belongs to the subfamily Hydroporinae as well as the related genus Siettitia Abeille de Perrin, 1904 from France. The new genus shares with Siettitia the lateral stria on the pronotum entire, but differs from it in very wide subsquare head, prosternal process in contact with the lobed anterior projection of metasternum, absence of fusion of the sterna 2 and 3, elytra not completely fused and several other peculiar features.