Omalium conoideum, Shavrin, 2025

Omalium conoideum sp. nov.

( Figs 6 View FIGURES 4–7 , 10–11 View FIGURES 8–15 )

Type material. Holotype ♂ ( Fig. 6 View FIGURES 4–7 ; dissected): ‘ TAIWAN: Nantou Hsien | Sun Kang 1600 m | 17.4.1991 | leg. Lo’ <printed>, ‘ HOLOTYPE | Omalium | conoideum sp.n. | Shavrin A.V. des. 2025’ <red, printed> ( NMW).

Description. Measurements: HW: 0.47; HL: 0.35; OL: 0.12; TL: 0.05; AL: 0.86; PL: 0.42; PWmax: 0.55; PWmin: 0.52; ESL: 0.71; EW: 0.72; MTbL: 0.35; MTrL: 0.23 (MTrL 1–4: 0.08; MTrL 5: 0.15); AW: 0.72; AedL: 0.35; BL: 2.50.

Habitus as in Fig. 6 View FIGURES 4–7 . Body reddish-brown, with distinctly paler elytra; antennomeres dark-brown, with paler antennomeres 3–5; mouthparts and legs yellow-brown. Punctation of head moderately dense, large and deep, denser in middle and on infraorbital portions; neck with dense small punctation; punctation of pronotum dense, about as that in middle part of head, finer and sparser in lateral and sparser in mediobasal portions; scutellum without punctures; punctation of elytra large and deep, slightly sparser than that in middle of pronotum, finer around scutellum and along suture; abdominal tergites without distinct punctation. Apical and lateroapical portions of clypeus with fine longitudinal microsculpture; scutellum with dense and fine isodiametric meshes; abdominal tergites with dense isodiametric microsculpture. Anterior part of head with elongate erect setation; anterior and posterior margins of pronotum with row of short cuticular fringe.

Head with relatively narrow and elongate clypeus, strongly elevated supra-antennal prominences and distinctly convex median and infraorbital portions; anteriomedian depressions relatively wide and narrow, reaching level of anterior margins of eyes; posteriolateral margins of clypeus strongly narrowed posteriad toward level of anterior third of eyes. Laterobasal parts of clypeus with narrow diagonal elevations between punctures; median portions in front of anteocellar foveae with elongate elevations between punctures; infraorbital portions with two indistinct and elongate wrinkles at level of anteocellar foveae and margins of eyes. Anteocellar foveae wide and deep, not convergent latero-apicad, reaching level of posterior third of eyes. Temples moderately short, convex. Postocular ridge indistinct and obtuse, with distance between posterior margin of eye and ridge about as long as diameters of four nearest ommatidia. Neck with short and longitudinal wrinkles between punctures. Ocelli located at about level of postocular ridges; distance between ocelli and eyes about twice as long as distance between ocellus and posterior margin of eye. Antennomere 2 suboval, about twice as long as basal antennomere, 3 distinctly narrower than 2, 4 about twice shorter than 3, 5 distinctly longer and slightly broader than 4, 6 slightly broader than 5, 7 slightly broader than 6, 8 slightly longer and distinctly broader than 7, 9–10 distinctly longer and broader than 8.

Pronotum convex, slightly broader than long, 1.1 times as broad as head, widest slightly above middle.Anterior angles widely rounded. Anterior margin somewhat straight, slightly concave in middle. Posterior margin rounded, slightly concave in middle. Lateral portions widely impressed in middle and laterobasal parts. Surface of disc with two wide and deep longitudinal depressions, significantly broadened in mediobasal portion. Medioapical part with indistinct small and oval depression. Surface between wide pronotal depressions strongly elevated. Middle part with irregular longitudinal elevations between punctures, slightly stronger in medioapical area. Each lateroapical part with rounded moderately wide elevation.

Elytra about as long as broad, 1.6 times as long as pronotum, indistinctly broadened posteriad. Dorsal surface of each elytron with strong elevations between punctures.

Metatarsi 1.5 times as long as metatibia.

Abdomen as broad as elytra, with two small round wing-folding patches in middle of abdominal tergite IV.

Male. Posterior margin of abdominal tergite VIII straight. Posterior margin of abdominal sternite VIII widely sinuate. Aedeagus with moderately broad basal portion, gradually narrowed toward wide and elongate median lobe; median lobe from apical third gradually narrowed toward rounded apex; mediolateral portions with narrow elongate accessory plates curved apically; parameres short and narrow, reaching middle of median lobe, each with narrow apex, and one long and two short apical setae; internal sac wide and moderately long, with several long spines in apical and middle portions ( Fig. 10 View FIGURES 8–15 ). Lateral aspect of the aedeagus as in Fig. 11 View FIGURES 8–15 .

Female unknown.

Comparative notes. Based on the shape of the aedeagus, O. conoideum sp. nov. belongs to the Oxyacanthae group ( Zanetti 1987; Shavrin 2023a). Based on the length of the body, and the general shape of the aedeagus with significantly shortened parameres and the presence of long spines in apical part of the internal sac, O. conoideum sp. nov. is similar to O. alticola Cameron, 1941 , known from the Himalayan Region ( Shavrin 2023a) and also from Sichuan ( Shavrin 2025a), and to O. khmericum Shavrin, 2020 , recently described from northern Laos ( Shavrin 2020). Omalium conoideum sp. nov. can be distinguished from O. alticola by the slightly broader apical part of the pronotum, denser punctation and coarser elevations between punctures of the pronotum and the elytra, and significantly narrower median lobe. Based on the punctation of the forebody and the shape of narrower median lobe, O. conoideum sp. nov. is more similar to O. khmericum , but can be distinguished from it by the darker body, the shape of the pronotum widest slightly above middle (pronotum of O. khmericum is widest in or slightly before the middle), and the slightly narrower elytra. From both species it differs by the different structure of the internal sac and details of the external morphology of the aedeagus.

Distribution. Omalium conoideum sp. n ov. is known only from the type locality in Nantou Hsien, Taiwan.

Etymology. The specific epithet is the Latin adjective conoideus, - a, - um (similar). It alludes to the similarity of the shape of the aedeagus with that of O. alticola .

Bionomics. The specimen was collected at an elevation of 1600 m a.s.l. Detailed bionomical data are unknown.