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

description: 3.3.2. Omalium pratense sp. nov.
(Figs 31, 34–36, 39)
Type material examined. Holotype ♂ (Fig. 31; dissected; left apical part of paramere missing): CHINA: SHAANXI: ‘CHINA (S-Shaanxi) Qinling Shan | pass on r[oa]d Zhouzhi-Foping | 105 km SW Xi`an, N slope | 1990 m, 33°44´N / 107°59´E | (small creek vall[ey]./mix[ed].decid[uous]. | for[est]./bamboo/small meadows) | 2./ 4.VII.2001 Wrase [01]’ <printed>, ‘HOLOTYPE | Omalium | pratense sp. nov. | Shavrin A.V. des. 2025’ <red, printed> (cSch).
Description. Measurements: HW: 0.50; HL: 0.35; OL: 0.17; TL: 0.03; AL: 0.85; PL: 0.41; PWmax: 0.62; PWmin: 0.42; ESL: 0.80; EW: 0.90; MTbL (holotype): 0.40; MTrL: 0.19 (MTrL 1–4: 0.07; MTrL 5: 0.12); AW: 0.82; AedL: 0.60; BL: 2.80.
Habitus as in Fig. 31. Head, pronotum and abdomen dark-brown (laterobasal and basal margins of pronotum slightly and apical part of abdomen and paratergites distinctly paler); antennomeres 6–11 and elytra brown; mouthparts, antennomeres 1–5 and legs yellowish. Head with irregular and moderately large punctation, slightly denser in middle and on infraorbital portions; neck with sparse and fine punctation; punctation of pronotum irregular, larger and deeper than that in middle portion of head, finer and sparser in lateral and mediobasal portions; punctation of elytra about as that on pronotum, denser around scutellum, finer and sparser in middle; abdomen without visible punctation. Anterior portion of clypeus with fine transverse microreticulation, laterobasal portions of clypeus with fine diagonal meshes, portions between apical margins of eyes and clypeus with distinct elongate microsculpture; scutellum without meshes; abdominal tergites with dense transverse sculpture.
Head 1.4 times as broad as long, with broad distinctly elevated clypeus and moderately wide and deep anteriomedian depressions, reaching level of apical margins of eyes; posteriolateral margins of clypeus relatively strongly narrowed posteriad and reaching level of anterior third of eyes. Latero-apical margin between anterior margin of eyes and clypeus with small semicircular notch. Dorsal surface with irregular transverse elevations between punctures in middle; postocular portions with two indistinct, narrow longitudinal wrinkles. Anteocellar foveae narrow, linear, reaching level of middle length of eyes. Temples very short, from posterior margins of eyes strongly narrowed toward neck. Apical part of neck without depression. Ocelli located slightly below level of posterior margins of eyes; distance between ocelli 1.4 times as long as distance between ocellus and posterior margin of eye. Apical maxillary palpomere about three and a half times as long as penultimate segment. Antenna with elongate antennomeres 4–7 and transverse 8–10; 3 distinctly narrower than 2, 4 distinctly shorter than 3, 5 broader than 4, 6 slightly longer and broader than 5, 7 indistinctly shorter and broader than 6, 8 broader than 7, 9–10 broader than 8, apical antennomere about twice as long as 10.
Pronotum transverse, 1.5 times as broad as long, 1.2 times as broad as head, from widest middle distinctly more narrowed posteriad than anteriad. Anterior margin rounded, not protruded anteriad, indistinctly concave in middle. Laterobasal portions not concave in front of subacute hind angles. Laterobasal portions widely impressed and relatively deeply impressed. Surface of disc with two indistinct longitudinal depressions, broadened in mediobasal portion; medioapical portion without depression. Middle portion without longitudinal elevations between punctures; each latero-apical portion with distinct longitudinal elevations.
Elytra 1.1 times as broad as long, 1.9 times as long as pronotum; hind margins straight. Dorsal surface of each elytron with irregular and moderately fine longitudinal elevations, more distinct in mediolateral and apical portions.
Abdomen slightly narrower than elytra.
Male. Posterior margin of abdominal tergite VIII truncate. Posterior margin of abdominal sternite VIII slightly sinuate.Aedeagus with wide and moderately short basal portion, slightly narrowed toward median lobe; median lobe elongate, from slightly broadened basal part indistinctly narrowed apically toward widely rounded apex; accessory plates relatively short and narrow; parameres moderately narrow, slightly narrowed apically, reaching preapical part of median lobe, each with three moderately short apical setae; internal sac wide and relatively short, with two small oval structures in basal part (Fig. 34). Lateral aspect of the aedeagus as in Fig. 35; apical portion of median lobe (lateral view) relatively wide, gradually narrowed toward subacute apex (Fig. 36).
Female unknown.
Comparative notes. Based on the general shapes of the body and the the aedeagus, O. pratensum sp. nov. is similar to the Palaearctic O. littorale Kraatz, 1857, widely distributed from Europe to Central Asia (Shavrin & Khachikov 2023; Zanetti 1987, 2002, 2006, 2011). It can be distinguished from it by the significantly shorter temples and slightly broader apical part of the median lobe.
Distribution. Omalium pratense sp. nov. is known only from the type locality in Qinling Shan mountain range, Shaanxi, China (Fig. 39).
Etymology. The specific epithet is the Latin adjective pratensis, - is, - e (living in meadows). It alludes to the holotype having been collected in a meadow.
Bionomics. The holotype was collected at elevation 1990 m a.s.l. by sifting in mixed deciduous forest with bamboo and small meadows.
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 511-514, DOI: 10.11646/zootaxa.5588.4.1, http://zenodo.org/record/14896684