Review of the genus Omalium Gravenhorst, 1802 (Coleoptera: Staphylinidae: Omaliinae: Omaliini) of China Author Shavrin, Alexey V. 0000-0001-6487-4530 Institute of Life Sciences and Technologies, Daugavpils University, Vienibas 13, Daugavpils, LV- 5401, Latvia ashavrin@hotmail.com text Zootaxa 2025 2025-02-18 5588 4 501 543 https://doi.org/10.11646/zootaxa.5588.4.1 journal article 308253 10.11646/zootaxa.5588.4.1 e8d80c74-68cf-4598-9172-65280e118626 1175-5326 14896684 444F5F59-9228-4100-9135-DF824FF9BACA 3.4.3. Omalium contiger sp. nov. ( Figs 18–19 , 33, 44–46, 48) Type material examined. Holotype ♂ ( Fig. 33 ): CHINA : SICHUAN : ‘CHINA, S-Sichuan , road | 56 km E Xichang- Zhaojue , | Mt. WenLin pass, 3200 m , | ~ 27°52´N , 102°30´E , | 5.–20. VI.2017 , leg. Reuter’ <printed>, ‘HOLOTYPE | Omalium | contiger sp. nov. | Shavrin A.V. des. 2025’ <red, printed> (cF, to be eventually deposited in Naturkundemuseum Erfurt, Germany). Paratypes ( 15 ♂♂ , 11 ♀♀ ): CHINA : SICHUAN : 2 ♂♂ (dissected; one specimen without right elytron), 1 ♀ (dissected; left elytron missing): same data as the holotype, with additional printed label: ‘ Omalium | sp. | det. Zanetti 2018’ ( 1 ♂ : cSh ; 1 ♂ , 1 ♀ : cF) ; 3 ♂♂ (two specimens dissected): ‘ CHINA , S-Sichuan , | S Yanyuan , Chuandongzi | massif, ~ 27°21`05``N , | 101°30´26´´E , 3200 m | 8.–19.VI.2017 ,leg. Reuter’ <printed> ( 1 ♂ : cSh ; 2 ♂♂ : cF) ; 4 ♂♂ , 3 ♀♀ : ‘ CHINA , S-Sichuan , | S Yanyuan , Chuandongzi- | Massif , 27°20`22``N , | 101°32´43´´E , 4100 m | 9.–19.VI.2017 ,leg. Reuter’ <printed>’, ‘ Omalium | sp. | det. Zanetti 2018’ <printed> ( 2 ♂♂ , 1 ♀ : cSh ; 2 ♂♂ , 2 ♀♀ : cF) ; YUNNAN : 2 ♂♂ (one specimen dissected), 4 ♀♀ : ‘ CHINA : Yunnan | above Dali , 2500–2700 m | 8.–18.IV.1999 | leg. W. SCHAWALLER’ <printed> ( 1 ♂ , 2 ♀♀ : cSh ; 1 ♂♂ , 2 ♀♀ : SMNS ) ; 1 ♂ (dissected): ‘ CHINA : Yunnan , Dali | Cangshan ca 2500 m | 10.IV.2003 in moss | G. de Rougemont leg.’ ( OUMNH ) ; 3 ♂♂ (two specimens dissected), 3 ♀ : ‘ CHINA : Yunnan , Dali | Cangshan ca 2500 m | 10.IV.2003 stream moss | G. de Rougemont leg.’ ( 2 ♂♂ , 2 ♀♀ : cSh ; 1 ♂ , 1 ♀ : OUMNH ). All paratypes with additional red printed label: ‘ PARATYPE | Omalium | contiger sp. nov. | Shavrin A.V. des. 2025’. Description. Measurements (n=27): HW: 0.47–0.60; HL: 0.35–0.41; OL: 0.12–0.15; TL: 0.08–0.10; AL ( holotype ): 1.02; PL: 0.40–0.51; PWmax: 0.60–0.67; PWmin: 0.55–0.60; ESL: 0.85–0.89; EW: 0.90–0.94; MTbL ( holotype ): 0.38; MTrL ( holotype ): 0.25 (MTrL 1–4: 0.08; MTrL 5: 0.17); AW: 0.85–0.89; AedL: 0.67–0.77; BL: 2.42–3.70 ( holotype : 3.00). Habitus as in Fig. 33 . Body brown to reddish-brown, usually with slightly darker head and abdomen (lateral parts of pronotum and lateroapical and lateral portions of elytra sometimes slightly paler); antennomeres 6–11 brown; mouthparts, antennomeres 1–5 and legs yellow-brown; tarsi yellowish. Punctation of head irregular and variable: fine and significantly sparser in middle or distinctly denser, larger and deeper in middle and on infraorbital portions; neck with sparse and fine punctation; punctation of pronotum dense, about as that in middle portion of head or sparser and finer, finer and sparser in middle and/or mediobasal portion, distinctly sparser in lateral parts; punctation of elytra dense, larger and coarser than that on pronotum; abdominal tergites without or with sparse, fine and sometimes indistinct punctation.Apical part of clypeus with distinct fine microsculpture: transverse in apical and in middle, and diagonal on supra-antennal elevations; scutellum with fine isodiametric microreticulation. Anterior and posterior margins of pronotum with row of cuticular setae, sometimes slightly longer on apical margin. Head 1.3–1.4 times as broad as long, with broad clypeus usually strongly narrowed posteriad toward level of middle or posterior third of eyes, with deep and wide anteriomedian depressions, reaching anterior third of eyes. Median part and infraorbital portions usually strongly elevated. Latero-apical margin between anterior margin of eyes and clypeus with small semicircular notch. Dorsal surface with irregular elevations between punctures: longitudinal or diagonal in laterobasal portions of clypeus, transverse or diagonal in middle and on infraorbital portions; irregular elevations on postocular portions sometimes forming indisinct three to four longitudinal wrinkles.Anteocellar foveae wide and deep, distinctly convergent latero-apicad toward level of middle length of eyes, sometimes connected with lateral margins of clypeus. Temples 1.5 times as long as longitudinal length of eye, from posterior margins of eyes gradually narrowed toward neck, sometimes with widely rounded hind angles. Apical part of neck narrowly and moderately deeply depressed, with several short and narrow elevations; middle portion sometimes distinctly elevated. Distance between ocelli 1.5–1.7 times as long as distance between ocellus and posterior margin of eyes. Apical maxillary palpomere two and a half to three times as long as penultimate segment. Antenna with elongate antennomeres 4–6, slightly transverse 7–8 and distinctly transverse 9–10; 4 about as long as broad, significantly shorter than 3, 5 longer and slightly broader than 4, 6 slightly broader than 5, 7–8 slightly longer and broader than 6, 9–10 distinctly broader than 8. FIGURE 48. Distribution of Omalium in China: O. contiger (rounds), O. schuelkei (squares), O. bambusaphilum (triangle). Pronotum 1.3–1.5 times as broad as long, widest in preapical portion, widely rounded apicad and distinctly narrowed posteriad. Apical angles not or slightly protruded anteriad. Anterior margin slightly rounded, not protruded anteriad, sometimes slightly concave in middle. Mediolateral and laterobasal margins widely and deeply impressed. Surface of disc with two long and wide longitudinal depressions distinctly broadened in mediobasal portion; medioapical portion without or with narrow depression; surface between all pronotal depressions narrowly elevated; each lateroapical portion with additional narrow and elongate elevation, from apical part reaching about middle. Middle portion without or with irregular and fine longitudinal and transverse elevations between punctures, more visible in apical and lateral portions. Elytra 1.7 times to twice as long as pronotum, somewhat subparallel or slightly broadened posteriad, some specimens with indistinctly concave lateral margins in about middle. Dorsal surface of each elytron with irregular transverse and subdiagonal elevations between pucntures, usually coarser in mediolateral portions of each elytron. Metatarsi about 1.5 times as long as metatibia. Abdomen slightly narrower than elytra, with two transverse wing-folding patches in middle of abdominal tergite IV and two smaller oval patches in middle of tergite V, invisible in some specimens; abdominal tergites III–VI sometimes with narrow or wide intersegmental membranes. Male. Posterior margin of abdominal tergite VII truncate or rounded. Posterior margin of abdominal sternite VIII widely and slightly sinuate. Aedeagus with wide basal portion, slightly narrowed toward median lobe; median lobe narrow, strongly elongate, from middle slightly broadened apicad and from preapical portion slightly narrowed toward obtuse apex; accessory plates narrow, short, with bilobed apical part; parameres narrow, reaching middle part of median lobe, each with three long apical setae; internal sac wide and moderately long, with two small suboval sclerotized structures in basal portion ( Fig. 44 ). Lateral aspect of the aedeagus as in Fig. 45 ; apical portion of median lobe (lateral view) elongate, with rounded apex, slightly curved ventrad, with distinctly broadened dorsoventral portion ( Fig. 46 ). Female. Posterior margin of abdominal tergite VIII truncate. Posterior margin of abdominal sternite VIII rounded. Accessory sclerite with moderately wide basal portion and elongate narrow median part, with subacute apex ( Fig. 18 ). Spermatheca as in Fig. 19 . Comparative notes. Based on the body length, proportions of the antennomeres, the shape of the pronotum widest in apical third and the presence of elongate median lobe, O. contiger sp. nov. is similar to the Himalayan O. scapulare Coiffait, 1982 , known from India and Nepal ( Shavrin 2023a ). It can be distinguished from it by the finer longitudinal wrinkles on infraorbital portions, more visible on postocular parts, slightly more transverse pronotum, different shape of the female accessory sclerite, narrower median lobe, narrower and shorter parameres and other details of the morphology of the aedeagus. Distribution. Omalium contiger sp. nov. is known from several localities in Sichuan and Yunnan , China ( Fig. 48 ). Etymology. The specific epithet is the Latin noun contiger (spear-bearer). It alludes to the shape of the median lobe. Bionomics. Specimens were collected at elevations from 2500 to 4100 m a.s.l. Specimens from Yunnan were sifted from wet mosses near streams.