Omalium kurilicum, Shavrin, 2025

Shavrin, Alexey V., 2025, Review of the genus Omalium Gravenhorst, 1802 (Coleoptera: Staphylinidae: Omaliinae: Omaliini) of Siberia and Far Eastern Russia, with notes on some species from Mongolia and Japan, Zootaxa 5646 (2), pp. 199-235 : 221-222

publication ID	https://doi.org/10.11646/zootaxa.5646.2.2
publication LSID	lsid:zoobank.org:pub:88AD7151-007C-4418-B396-8FE3A10EE6E2
DOI	https://doi.org/10.5281/zenodo.15989956
persistent identifier	https://treatment.plazi.org/id/F91B8795-8327-BC5B-8BE0-904C0FE2FABC
treatment provided by	Plazi
scientific name	Omalium kurilicum
status	sp. nov.

Treatment

3.2.4.5. Omalium kurilicum sp. nov.

( Figs 16 View FIGURES 10–19 , 29–30 View FIGURES 25–30 , 32 View FIGURE 32 , 34 View FIGURES 33–35 )

Omalium sp. : Shavrin & Makarov 2019: 47.

Paratypes: 2 ♀♀ (one specimen dissected; one specimen with additional printed label: ‘ Omalium [handwritten] | cf. rivulare Payk. [handwritten] | det. M. Schülke 2004’): same data as the holotype ( cSch, cSh) ; 1 ♂ (dissected): ‘КУнашир, | междУречье рек | СаратовскаЯ и ТЯтина | 44°16’28’’N 146°07’09’’ | 5–8.VII.2014 | leg. Ю. и Л. СУндУковы [Kunashir, interfluve of Saratovskaya and Tyatina rivers […] leg. Yu. Sundukov & L. Sundukova]’ <printed> ( cSh). All paratypes with additional red printed label: ‘ PARATYPE | Omalium | kurilicum sp.n. | Shavrin A.V. des. 2025’.

Description. Measurements (n=4): HW: 0.65–0.70; HL: 0.45–0.47; OL: 0.20–0.24; TL: 0.04–0.05; AL (holotype): 0.97; PL: 0.50–0.55; PWmax: 0.82–0.85; PWmin: 0.77–0.78; ESL: 0.96–1.07; EW: 1.15–1.27; MTbL (holotype): 0.55; MTrL (holotype): 0.28 (MTrL 1–4: 0.12; MTrL 5: 0.16); AW: 0.87–1.25; AedL: 0.63–0.90; BL: 3.25–4.00 (holotype: 3.45).

Habitus as in Fig. 34 View FIGURES 33–35 . Head, pronotum and abdomen reddish-brown (lateral and basal portions of pronotum, paratergites and apical tergites of abdomen distinctly paler); elytra yellow-brown, with slightly darkened mediobasal portion; antennomeres 6–11 brown; mouthparts, antennomeres 1–5 and legs yellow. Head with irregular moderately dense punctation, finer and sparser on clypeus, denser, larger and deeper in middle, punctation of infraorbital portions about as that in middle but slightly finer; neck with dense moderately large punctation; punctation of pronotum dense and large, sparser in middle, lateral and mediobasal portions; punctation of elytra dense, but larger and deeper than that on pronotum, finer and sparser in middle; abdominal tergites without visible punctation or with fine, sparse and fine punctation in middle (paratype from Kunashir). Anterior portion of clypeus with fine transverse microsculpture, laterobasal parts of clypeus with dense diagonal meshes, middle portion with indistinct or distinct and dense diagonal microreticulation, infraorbital portions with dense longitudinal microsculpture; neck with transverse sculpture, invisible in holotype and one parartype in middle; scutellum with fine isodiametric meshes; abdominal tergites with dense and moderately coarse isodiametric sculpture. Anterior portion of head with erect elongate setation, each mediolateral part of clypeus and mediobasal part of infraorbital portion with long erect seta; lateral portions of pronotum with several short setae; abdominal tergites with dense and very short setation; posterior margin of pronotum and elytra (two paratypes) with row of short cuticular fringe.

Head 1.4 times as broad as long, with somewhat flattened (paratype from Kunashir) or slightly convex middle part and with distinctly elevated infraorbital portions; clypeus relatively wide, convex, with strongly explanated supra-antennal elevations; anteriomedian depressions relatively wide and deep, elongate, reaching level of anterior margin or anterior third of eyes; each posteriolateral margin of clypeus distinctly narrowed and stretching posteriad toward level of anterior third or middle of eye. Median part of head without or with fine irregular elevations between punctures, with three to four narrow elongate wrinkles on posterior parts of infraorbital portions. Anteocellar foveae suboval and deep, somewhat shortened or elongate and slightly convergent latero-apicad, reaching level of posterior third or middle of eyes. Temples short, strongly narrowed posteriad. Nuchal constriction moderately wide and deep. Ocelli large, located slightly below level of posterior margins of eyes; distance vetween ocelli 1.7 times to twice as long as distance between ocellus and posterior margin of eye. Antenna with slightly elongate antennomeres 4–7 and transverse 8–10; antennomere 4 short, slightly more than twice as long as 3, 5 indistinctly broader than 4, 6 slightly longer and broder than 5, 7 broader than 6, 8 broader than 7, 9–10 distinctly broader than 8, apical antennomere 1.3–1.4 times as long as preceding segment, from middle strongly narrowed toward subacute apex.

Pronotum disitnctly convex, 1.5–1.6 times as broad as long, 1.5–1.6 times as broad as head, from widest middle more narrowed posteriad than anteriad toward obtuse hind angles.Anterior angles slightly narrowed toward relatively wide apical angles. Anterior margin widely rounded, slightly concave in middle, slightly shorter than rounded posterior margin. Lateral portions realtively widely impressed and distinctly explanate, each with deep elongate impressions behind middle. Surface of disc with two elongate longitudinal depressions, significantly deepened in mediobasal portion; each lateroapical portion with curvad elongate elevation, reaching middle of pronotum; surface between longidinal elevations slightly elevated.

Elytra slightly broader than long, 1.9 times as long as pronotum, slightly broadened postreriad. Dorsal surface of each elytron (except median areas along suture) with moderately strong longirudinal elevations between punctures.

Abdomen slightly narrower than elytra.

Male. Posterior margin of abdominal tergite VIII straight. Posterior margin of abdominal sternite VIII straight or slightly rounded. Aedeagus with broadened basal portion, gradually narrowed toward middle; median lobe relatively narrow, elongate, from widest middle gradually narrowed toward small rounded apex, from above middle with narrow rounded lateral projections; parameres wide, significantly shorter than apex of median lobe, distinctly narrowed in apical portions, each with two long apical and one shorter preapical setae; internal sac narrow and long, with small paired oval sclerotized structures in basal portion ( Fig. 29 View FIGURES 25–30 ). Lateral aspect of the aedeagus as in Fig. 30 View FIGURES 25–30 ; apical portion of median lobe (lateral view) with rounded apex, with several ventrolateral teeth, elongate basad, with largest ventrolateral tooth relatively long.

Female. Posterior margins of abdominal tergite VIII and sternite VIII truncate. Accessory sclerite elongate, from widest basal portion gradually narrowed toward subacute apex (Fig. x). Spermatheca not recognized.

Comparative notes. Based on general shape and coloration of the body, and shape of the aedeagus, O. kurilicum sp. nov. is similar to O. pseudojaponicum Shavrin, 2025 , recently described from Gansu, China ( Shavrin 2025). It can be distinguished from it by the more elongate antennomere 7, denser punctation of the pronotum, shape of the slightly broader pronotum, more narrowed posteriad than anteriad, shape of shorter and broader median lobe of the aedeagus and slightly different shapes of ventrolateral teeth on it, and other details of the morphology of the aedeagus.

Distribution. Omalium kurilicum sp. nov. is known from two localities in Iturup and Kunashir islands, Kuril islands, Russia ( Fig. 16 View FIGURES 10–19 ).

Etymology. The specific epithet derived from the type locality (Kuril islands) of the species.

Bionomics. Detailed bionomical data are unknown.

Remarks. Shavrin & Makarov (2019) recorded it as “ Omalium sp. ” for Kunashir Island (see material above).