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

description: 3.5.2. Omalium confertum sp. nov.
(Figs 24–25, 39, 63, 66–68)
Type material examined. Holotype ♂ (dissected): CHINA: SICHUAN: ‘CHINA, Sichuan, | NW Heishui, 3428 m | 32°11´29´´N, 102°39´30´´E | 14–20.VI.2018,leg. Reuter’ <printed>, ‘HOLOTYPE | Omalium | confertum sp. nov. | Shavrin A.V. des. 2025’ <red, printed> (cF, to be eventually deposited in Naturkundemuseum Erfurt, Germany).
Paratypes: 1 ♀ (Fig. 63; dissected): same data as the holotype, with additional printed label: ‘HOLOTYPE | Omalium | confertum sp. nov. | Shavrin A.V. des. 2025’ <red, printed> (cF).
Description. Measurements (n=2): HW: 0.52–0.57; HL: 0.42–0.43; OL: 0.15; TL: 0.10; AL (holotype): 1.23; PL: 0.45; PWmax: 0.70; PWmin: 0.63–0.64; ESL: 0.78–0.85; EW: 0.86–0.87; MTbL (holotype): 0.51; MTrL (holotype): 0.22 (MTrL 1–4: 0.10; MTrL 5: 0.12); AW: 0.87–0.90; AedL: 0.55; BL: 2.90–2.95 (holotype).
Habitus as in Fig. 63. Body dark-brown; antennomeres 7–11 brown; mouthparts, antennomeres 1–6 and legs yellowish-brown; tarsi yellow. Punctation of head irregular: finer and sparser in basal portions of clypeus, denser and larger in middle, and denser and coarser on infraorbital parts, with portions between ocelli without or with two (paratype) moderately fine punctures; neck with dense and large punctation about as that in middle part of head; pronotum with irregular moderately dense punctation, finer and sparser in medioapical portion, larger, deeper and denser in middle and sparser in mediobasal part, lateral parts without punctures except of latero-apical and laterobasal portions with fine and sparse punctation; elytra with dense and coarse punctation, significantly larger and deeper than that in middle of pronotum, finer around scutellum and along suture; abdomen without visible punctation except of abdominal tergite V with indistinct sparse and fine punctation. Anterior part of clypeus with dense and transverse and laterobasal parts with longitudinal microreticulation, median and posterior portions of head without meshes; neck, pronotum and elytra without microsculpture; abdomen with dense and fine isodiametric sculpture.
Head 1.2–1.3 times as broad as long, with strongly elevated clypeus and moderately wide and deep anteriomedian depressions; posteriolateral margins of clypeus stretching posteriad toward level of middle length of eyes. Latero-apical portions between eyes and clypeus narrowly and deeply depressed, with distinct semicircular notch between anterior margin of eyes and antennal insertion. Dorsal surface with strong elevations: longitudinal and diagonal in laterobasal parts of clypeus and subdiagonal on infraorbital portions. Anteocellar foveae significantly widened and deep, strongly convergent latero-apicad toward level of middle lengtht of eyes and connected with latero-apical depressions. Temples 1.5 times as long as longitudinal length of eye. Apical part of neck slightly and narrowly depressed. Distance between ocelli about twice as long as distance between ocellus and posterior margin of eye. Apical maxillary palpomere about three times as long as penultimate segment. Antenna with slightly transverse antennomeres 8–10; antennomere 4 1.3 times as long as 3, 5 slightly longer than 4, 6 indistinctly broader and longer than 5, 7 slightly shorter than 6, 8 slightly broader than 7, 9–10 slightly shorter and distinctly broader than 8.
Pronotum 1.5 times as broad as long, 1.2–1.3 times as broad as head, widest in middle, with strongly convex middle part. Apical agles widely rounded, not protruded anteriad. Hind angles obtuse. Each lateral portion widely impressed, deeper slightly below middle. Surface of disc with two large and deep longitudinal depression.
Elytra 1.1 times as broad as long, 1.7–1.8 times as long as pronotum, somewhat subparallel and slightly concave in about middle; lateral portions relatively widely impressed, hind margins rounded. Dorsal surface of each elytron with strong irregular elevations, subdiagonal in mediobasal, transverse in middle and longitudinal in apical portions.
Abdomen slightly broader than elytra.
Male. Posterior margin of abdominal tergite VIII slightly and sternite VIII widely and deeply sinuate. Aedeagus with wide basal portion, gradually narrowed toward median lobe; median lobe narrow, elongate, from narrower basal part slightly narrowed toward preapical part, with rounded apex; accessory plates narrow, elongate and rounded apically; parameres from narrowest basal parts significantly broadened in middle and narrowed toward apex, reaching level of preapical part of median lobe, each with one long and three short apical setae; internal sac long and wide, with two elongate sclerotized structures in basal part (Fig. 66). Lateral aspect of the aedeagus as in Fig. 67; apical portion of median lobe (lateral view) hook-shaped, with crenulate ventrolateral margin and rounded apex (Fig. 68).
Female. Posterior margin of abdominal tergite VIII and sternite VIII truncate. Accessory sclerite with wide basal portion and median part, strongly narrowed toward narrow apical part with acute apex (Fig. 24). Spermatheca as in Fig. 25.
Comparative notes. Based on the proportions of the forebody and antennomeres, coarse punctation of the elytra and the general shape of the aedeagus, O. confertum sp. nov. is similar to O. latocavum Shavrin, 2023, recently described from central Nepal (Shavrin 2023a). The new species can be distinguished from it by the smaller body, darker coloration, sparser punctation of the head and the pronotum, slightly longer temples more narrowed posteriad, more transverse pronotum with more widely impressed lateral portions and wider preapical part, slightly shorter elytra, different shape of the preapical portion of the median lobe and the female accessory sclerite, and other details of the morphology of the aedeagus.
Distribution. Omalium confertum sp. nov. is known only from the type locality in Sichuan, China (Fig. 39).
Etymology. The specific epithet is the Latin adjective confertus, - a, - um (dense or crowded). It alludes to the dense punctation of the forebody.
Bionomics. Specimens were collected at elevation 3428 m a.s.l. The detailed bionomical data are unknown.
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 527-529, DOI: 10.11646/zootaxa.5588.4.1, http://zenodo.org/record/14896684