New records of Hydraena schuleri Ganglbauer, 1901 from Slovakia (Coleoptera, Hydraenidae)

Hydraena schuleri Ganglbauer, 1901 was rediscovered after 18 years in Starý Potok, a small stream in eastern Slovakia, and we recorded it, for the first time, from the small rivers Stará Rieka and Udava in southern and eastern Slovakia. Adults were collected mainly from submerged moss growing on rocks in shallow water, where they were found together with Hydraena minutissima Stephens, 1929, H. pulchella Germar, 1824, H. pygmaea Waterhouse, 1833; Ochthebius colveranus Ferro, 1979, O. melanescens Dalla Torre, 1877, and O. metallescens Rosenhauer, 1847. We provide illustrations of the habitus and aedeagus, and a distribution map.