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) Author Jia, Fenglong Institute of Entomology, Life Science School, Sun Yat-sen University, Guangzhou, 510275, Guangdong, China Author Liang, Zulong Institute of Entomology, Life Science School, Sun Yat-sen University, Guangzhou, 510275, Guangdong, China Author Fikacek, Martin Department of Entomology, National Museum, Cirkusova 1740, CZ- 193 00 Praha 9, Czech Republic & Department of Zoology, Faculty of Science, Charles University, Vinicna 7, CZ- 128 44 Praha 2, Czech Republic https://orcid.org/0000-0002-2078-6798 mfikacek@gmail.com text Deutsche Entomologische Zeitschrift 2020 67 1 35 49 http://dx.doi.org/10.3897/dez.67.50078 journal article http://dx.doi.org/10.3897/dez.67.50078 1860-1324-1-35 56BB973DBE4E47AEBC98C1F1151C41C4 42CBDE9B2C305189858C3A18211EA41F Himalcercyon franzi sp. nov. Figures 1E-H , 3 , 4 Type locality. China, Xizang Autonomous Region, Motuo County, track from Dayandong to Hanmi, 2200-2400 m a.s.l. [GPS ca 29.4283N , 95.0498E ]. Material examined. Holotype : CHINA ● 1 ♂; Xizang, Motuo County, Dayandong-Hanmi; 2200-2400 m a.s.l.; 13 Aug 2005, Tang Liang leg.; SYSU [verbatim label data: "CHINA, Xizang, Motuo Coun., Dayandong-Hanmi, alt. 2200-2400 m, 13.viii.2005, TANG Liang leg."]. Paratypes : CHINA ● 9; same data as for holotype; SYSU ● 4; Xizang, Motuo County, Nage-Dayandong; 2900-3300 m a.s.l.; 12 Aug 2005; Tang Liang lgt.; SYSU ● 1; Xizang, Motuo County, Nage-Dayandong; 2900-3300 m a.s.l.; 12 Aug 2005; Tang Liang lgt.; NMPC. Description. Form and color. Body size 2.5-2.8 mm (2.6 mm in holotype), body width 1.5-1.7 mm (1.55 mm in holotype), widest at anterior third of elytra, arcuately narrowing posteriad (Fig. 1E ). Dorsum dark brown; head of some specimens with paler clypeus; pronotal lateral margins yellow brown; elytral apices and posterior half of lateral elytral margins slightly paler; epipleuron reddish brown; antenna, maxillary and labial palpi reddish brown; legs reddish brown, with darker femora. Head. Clypeus with moderately dense fine setiferous punctures, smooth between punctures. Frons with punctures coarser and somewhat denser than those on clypeus, smooth between punctures. Mentum 2 x wider than long, rugose, with dense coarse punctures (Fig. 3A ), slightly concave anteriorly. Antenna with pedicel ca 0.2 x as long as scape, pedicel ca. as long as antennomeres 3 and 4 combined, cupule small (Fig. 3D ). Thorax. Pronotum with punctation similar to that on frons, interstices without microsculpture; lateral marginal bead shortly overlapping to anterior margin but not to posterior margin, stopping at posterior angle. Scutellar shield smooth, with three to five punctures. Elytral striae sharply impressed (Figs 1E-F ), striae 6, 8, and 9 not reaching base; intervals with much finer and sparser punctures than on pronotum, each interval puncture bearing a fine short seta (Fig. 3G ), interstices between punctures smooth. Epipleuron with bare outer and pubescent inner portion delimited from each other by a fine ridge, inner pubescent part narrower than the outer part, reaching the level of posterior part of metaventrite. Mesoventral elevation arrowhead-shaped, ca 2.0 x longer than wide, densely pubescent (Fig. 3C ). Metaventrite with large median elevation, finely and sparsely punctate (Fig. 3F ), interstices without microsculpture; lateral portions microsculptured with sparse coarse punctures and dense pubescence. Legs with trochanters densely pubescent, femora with sparse and moderately coarse punctures, interstice between punctures with fine microsculpture consisting of transverse lines. Male genitalia. Middle lobe of abdominal sternite IX wide, shorter than lateral struts (Fig. 1H ). Aedeagus (Fig. 1G ) with median lobe ca 0.8 x as long as tegmen; paramere ca 1.5 x as long as phallobase. Paramere gradually narrowed from base to apex, truncate apically, widened inwards to form a process with a few setae. Median lobe broader than paramere, gradually narrowing in apical third, apex pointed, gonopore subapical. Etymology. The species is named after Dr Franz Hebauer, a German taxonomist of the Hydrophiloidea who recognized and described Himalcercyon as a subgenus of Cercyon . Distribution. Only known from the type locality in the eastern Himalaya (Motuo county, Xizang Autonomous Region, China) (Fig. 4 ).