The Japanese species ofHelochares (Crephelochares)(Coleoptera: Hydrophilidae), with description of a new species from Honshu

Abstract

Helochares orbus, sp.n. belonging to the subgenus Crephelochares Kuwert, 1890, is newly described from the central part of Honshu, Japan. It is apparently distinguished from all others hitherto described in the subgenus by the male genitalia, especially by the parameres bearing an inner dentiform projection subapically and being acutely pointed at the apex as well as by the structures of ventral sclerites of the median lobe. New records are given for H. (C.) abnormalis (Sharp). A key to the Japanese species of the subgenus is provided.