Omalium bambusaphilum Shavrin, 2025, sp. nov.
Creators: name: Shavrin, Alexey V.
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Staphylinidae
Omalium
Omalium bambusaphilum

description: 3.5.1. Omalium bambusaphilum sp. nov.
(Figs 22–23, 48, 52, 59–61)
Type material examined. Holotype ♂ (dissected): CHINA: JIANGXI: ‘CHINA: Jiangxi prov.[MF10] | Jinggangshan Mts., Songmuping | 26°34.7´N, 114°04.3´E, 1280 m | (stream valley), 27.iv.2011 | Fikáček, Hájek, Jia & Song’ <printed>, ‘cut and decaying tops of | bamboo trunks in a sparse | bamboo bush’ <printed>, ‘HOLOTYPE | Omalium | bambusaphilum sp. nov. | Shavrin A.V. des. 2025’ <red, printed> (NMPC).
Paratypes: CHINA: JIANGXI: 5 ♀♀ (one specimen dissected): same data as the holotype, with additional red printed label: ‘PARATYPE | Omalium | bambusaphilum sp. nov. | Shavrin A.V. des. 2025’ <red, printed> (2 ♀♀: cSh; 3 ♀♀: NMPC).
Description. Measurements (n=6): HW: 0.47–0.51; HL: 0.28–0.30; OL: 0.14–0.15; TL: 0.04–0.05; AL (holotype): 0.70; PL: 0.34–0.36; PWmax: 0.55–0.63; PWmin: 0.49–0.59; ESL: 0.64–0.79; EW: 0.73–0.81; MTbL (holotype): 0.27; MTrL (holotype): 0.19 (MTrL 1–4: 0.07; MTrL 5: 0.12); AW: 0.72–0.85; AedL: 0.55; BL: 2.45(holotype)–3.10.
Habitus as in Fig. 52. Head, pronotum and abdomen reddish-brown; lateral and basal portions of pronotum, elytra, paratergites (two paratypes) and intersegmental membranes of abdomen yellow-brown (parascutellar portion of elytra slightly darkened); antennomeres 6–11 brown; mouthparts, antennomeres 1–5 and legs yellowish. Punctation of head irregular, moderately fine and dense, denser in middle, infraorbital portions without punctures except of several fine punctures close to anteocellar foveae; neck with irregular moderately dense and fine punctures in mediobasal part; punctation of pronotum dense, distinctly larger and deeper than that in middle portion of head, with interspaces between pucntures in middle about as long as diameters of one to three nearest punctures, sparser and finer in lateral and mediobasal portion (one paratype with sparse and fine punctation in middle); punctation of elytra dense; abdominal tergites without visible punctation. Head with dense microsculpture: transverse in apical and diagonal in lateral portions of clypeus, transverse between level of anterior third of eyes, longitudinal and diagonal in middle, and longitudinal on infraorbital portions (two paratypes without visible sculpture in middle); neck without meshes; pronotum with indistinct fine isodiametric microreticulation; pronotum with dense isodiametric sculpture.
Head 1.6–1.7 times as broad as long, with moderately wide and deep anteriomedian depressions, almost reaching level of anterior third of eyes; posteriolateral parts of clypeus slightly narrowed posteriad, reaching level of anterior third of eyes. Latero-apical margin between anterior margin of eyes and clypeus with small semicircular notch. Infraorbital portions with elongate longitudinal wrinkles. Anteocellar foveae somewhat suboval, relatively deep, indistinctly convergent latero-apicad toward level of middle length of eyes. Temples short, about or more than three times shorter than longitudinal length of eyes, from posterior margin strongly narrowed toward neck; postocular ridges present, obtuse, with distance between posterior margin of eye and ridge about as long as one-two nearest ommatidia. Apical part of neck narrowly depressed in apical part, with irregular short and narrow elevations. Ocelli located slightly below level of postocular ridges; distance between ocelli slightly shorter than distance between ocellus and posterior margin of eye. Apical maxillary palpomere about three times as long as penultimate segment. Antenna with slightly transverse antennomeres 7–8 and distinctly transverse 9–10; 4–5 small, about as long as wide, 6 slightly longer and broader than 5, 7 slightly broader than 6, 8 slightly longer and broader than 7, 9–10 distinctly broader than 8, apical antennomere slightly less than twice as long as 10.
Pronotum 1.6–1.7 times as broad as long, 1.1–1.2 times as broad as head, from widest middle slightly more narrowed posteriad than anteriad. Apical angles widely rounded, not protruded anteriad. Anterior margin rounded, slightly concave in middle. Laterobasal portions not concave in front of obtuse hind angles. Lateral potions relatively deeply and widely impressed, deeper in middle and broader in laterobasal portions. Surface of disc with two moderately deep longitudinal and narrow, sometimes indistinct, medioapical depressions; surface between all pronotal depressions narrowly elevated. Middle part without elevations between punctures.
Elytra 1.1 times broader than long, 1.8 times to twice as long as pronotum. Mediolateral surface of each elytron with irregular longitudinal and diagonal elevations between punctures.
Metatarsi 1.4 times as long as metatibia.
Abdomen as wide as elytra or slightly broader, with wide intersegmental membranes between abdominal tergites III–V or III–VI.
Male. Posterior margin of abdominal tergite VIII slightly and sternite VIII widely and moderately deeply sinuate. Aedeagus with very wide basal portion, gradually narrowed toward median lobe; median lobe narrow, elongate, from basal part slightly broadened toward middle and from middle slightly narrowed toward small rounded apex; accessory plates short, narrow, distinctly curved and rounded apically; internal sac wide and relatively long (Fig. 59). Lateral aspect of the aedeagus as in Fig. 60; apical portion of median lobe (lateral view) hook-shaped, with slightly curved ventrodorsad subacute hind angle and rounded apex (Fig. 61).
Female. Posterior margin of abdominal tergite VIII truncate. Posterior margin of abdominal sternite VIII rounded. Accessory sclerite short, triangular, from widest basal portion strongly narrowed toward acute apex (Fig. 22). Spermatheca as in Fig. 23.
Comparative notes. Based on the general shape of the body and the aedeagus, the presence of the hook-shaped apical portion of the aedeagus (lateral view), the coloration of the body, with distinctly paler elytra, the short temples and the pronotum widest in middle, and the similar shape of the female accessory sclerite, O. bambusaphilum sp. nov. is similar to the Himalayan O. cariosum Cameron, 1924, known from India (Shavrin 2023a). The new species can be distinguished from it by the sparser and slightly larger punctation of the slightly more transverse pronotum, slightly narrower elytra, narrower and longer median lobe, the shape of hook-shaped apical part of the median lobe (lateral view), and broader apical parts of the parameres.
Distribution. Omalium bambusaphilum sp. nov. is known only from the type locality in Jinggangshan mountain range in Jiangxi, China (Fig. 48).
Etymology. The name of the new species is derived from the fact that the type specimens were collected in “bamboo bush” (genus Bambusa and related).
Bionomics. Specimens were collected at elevation 1280 m a.s.l. by sifting of cut and decaying tops of bamboo trunks.
description: Published as part of Shavrin, Alexey V., 2025, Review of the genus Omalium Gravenhorst, 1802 (Coleoptera: Staphylinidae: Omaliinae: Omaliini) of China, pp. 501-543 in Zootaxa 5588 (4) on pages 526-527, DOI: 10.11646/zootaxa.5588.4.1, http://zenodo.org/record/14896684