A review of the omicrine genera omicrogiton, mircogioton and peratogonus of china (Coleoptera, Hydrophilidae, Sphaeridiinae)

Abstract

The Chinese species of the genera Omicrogiton Orchymont, 1919, Peratogonus Sharp, 1884 and Mircogio­ton Orchymont, 1937 are reviewed, diagnosed and keyed. Mircogioton and Omicrogiton are reported for the first time from China, Peratogonus for the first time for mainland China. Five species are recognized: Omicrogiton coomani Balfour-Browne, 1939 (Guangdong, Hongkong), O. hainanensis sp. n. (Hainan), O. roberti sp. n. (Hainan), Mircogioton coomani Orchymont, 1937 (Yunnan), and Peratogonus reversus Sharp, 1884 (Guangdong, Jiangxi, Taiwan). Lectotype of Omicrogiton coomani is designated. Mircogioton cognitus (Malcolm, 1981), syn. n. is considered a junior subjective synonym of M. coomani Orchymont, 1939. Species of Mircogioton and Omicrogiton inhabit decaying banana trunks, whereas Peratogonus rever­sus was always collected from moist forest leaf litter.