A review of Himalcercyon stat. nov., with description of a new species from the Chinese Himalaya and an updated key to Asian genera of Megasternini (Coleoptera, Hydrophilidae)

Abstract

Himalcercyon Hebauer, 2002 stat. nov. is elevated to genus rank based on the unique form of its mesoventral elevation. The genus is reviewed, redescribed, and illustrated in detail. Two species are recognized: Himalcercyon mirus (Hebauer, 2002) comb. nov. from Nepal and H. franzi sp. nov. from Chinese Himalaya (Xizang Autonomous Region). Both species are illustrated and diagnosed. An updated key to the Asian genera of the tribe Megasternini (Coleoptera, Hydrophilidae, Sphaeridiinae) is provided, along with the SEM micrographs of ventral morphology of these genera. New replacement name Oreosternum nom. nov. is proposed for Oreocyon Hebauer, 2002 which is preoccupied by Oreocyon Marsh, 1872 (Mammalia, Oxyenidae) and Oreocyon Krumbiegel, 1949 (Mammalia, Canidae).