Omaliopsis obliquesignata, Shavrin, 2023

Shavrin, Alexey V., 2023, Four new species of the genus Omaliopsis Jeannel, 1940 (Coleoptera: Staphylinidae: Omaliinae: Omaliini) of China, Zootaxa 5380 (5), pp. 446-460 : 454-455

Omaliopsis obliquesignata sp. n.

( Figs 3 , 17 , 25–31 )

Type material. Holotype ♂ ( Fig. 3 ): ‘ CHINA: S-Shaanxi (Qinling Shan) | pass on rd. Zhouzhi – Foping , | 105 km SW Xi`an, N-slope, | 1990 m, 33°44’ N, 107°59’E | leg. M. Schülke [C01-01]’ <printed>, ‘2./ 4. VII. 2001, | small creek valley, mixed | deciduous forest, bamboo, | small meadows, dead wood, | mushrooms (sifted) [C01-01]’ <printed>, ‘Sammlung | M. Schülke | Berlin’ <printed>, ‘HOLOTYPE | Omaliopsis | obliquesignata sp. n. | Shavrin A.V. des. 2023’ <red, printed> (cSch).

Paratypes (9 ♂♂, 7 ♀♀): 9 ♂♂ (2 specimens dissected), 7 ♀♀ (2 specimens dissected): sama data as the holotype, with additional red printed label: ‘PARATYPE | Omaliopsis | obliquesignata sp. n. | Shavrin A.V. des. 2023’ (2 ♂♂, 2 ♀♀: cSh; 7 ♂♂, 5 ♀♀: cSch).

Description. Measurements (n=17): HW: 0.38–0.42; HL: 0.24–0.30; OL: 0.09–0.10; TL: 0.04–0.05; AL (holotype): 0.67; PL: 0.31–0.35; PW: 0.54–0.55; ESL: 0.64–0.67; EW: 0.72–0.73; MTbL (holotype): 0.32; MTrL (holotype): 0.18 (MTrL 1–4: 0.06; MTrL 5: 0.12); AW: 0.64–0.67; AedL: 0.36–0.47; BL: 1.92–2.37 (holotype: 2.10).

Habitus as in Fig. 3 . Body yellow-brown to reddish brown, with distinctly darker head and abdomen; basal and/or lateral portions of pronotum, middle and lateral portions of elytra, paratergites, apical margins of abdominal tergites and apex of abdomen yellowish; each elytron with narrow brownish spot in mediobasal and with moderately wide obligue spot in apical half, starting from about mediolateral margin toward medioapical part slightly not reaching suture, lateroapical portions of each elytron darkened in some specimens; antennomeres 7–11 brownish; mouthparts, antennomeres 1–6 and legs yellow. Punctation of head irregular and very sparse, denser in middle and sometimes without punctures between ocelli; punctation of pronotum about as that in middle portion of head, but denser, sparser and finer in medioapical and/or mediobasal portions; punctation of elytra about that in protonum, but slightly denser, sometimes denser and coarser around scutellum, finer and sparser along suture. Frontoclypeal part with fine transverse microreticulation, infraorbital portions with longitudinal meshes, middle of head without distinct microsculpture; pronotum and elytra without microreticulation; scutellum without or with fine transverse meshes; abdominal tergites with dense isodiametric sculpture.

Head 1.4–1.5 times as broad as long, with narrow frontoclypeal portion and distinctly convex supra-antennal elevations, forming very long linear parallel ridges reaching level of basal third of eyes; anteriomedian depressions moderately deep and elongate; anteocellar foveae short and deep, slightly longer than diameter of ocelli; dorsal margins near eyes with fine indistinct one or two elongate wrinkles. Antennomeres 5–8 progressively broadened apicad; antennomere 3 slightly shorter and distinctly narrower than 2, 4 slightly less than twice shorter than 3, 5 slightly broader than 4, 7 slightly longer and distinctly broader than 6, 7 indistinctly longer and broader than 6, 8 slightly broader than 7, 9–10 slightly longer and broader than 8.

Pronotum 1.5–1.7 times as broad as long, 1.3–1.4 times as broad as head, widest in about middle, slightly more narrowed posteriad than anteriad; basal part of surface of disc with two indistinct and shallow or distinct and moderately deep wide depressions.

Elytra slightly broader than long and twice as long as pronotum.

Metatarsi slightly less than twice shorter than metatibia.

Abdomen slightly narrower than elytra.

Male. Posterior margin of abdominal tergite VIII rounded ( Fig. 27 ). Posterior margin of abdominal sternite VIII widely emarginate ( Fig. 28 ). Aedeagus with moderately wide basal portion, gradually narrowed toward small rounded apex; parameres narrow, slightly broadened apically, not reaching apex of median lobe, with two moderately long apical setae; internal sac long and wide, with paired elongate and wide structures in basal portion and very short thin flagellum between them ( Fig. 25 ). Lateral aspect of the aedeagus as in Fig. 26 .

Female. Posterior margin of abdominal tergite VIII ( Fig. 29 ) and sternite VIII ( Fig. 30 ) rounded. Female accessoty sclerite leaf-shaped, short, from widest basal portion gradually narrowed toward rounded apex ( Fig. 31 ). Spermatheca not recognized.

Comparative notes. Based on the general shapes of the convex forebody and the aedeagus, and the lack of postocular ridges, O. obliquesignata sp. n. is similar to O. fraterna sp. n., O. hlavaci sp. n. and O. smetanai sp. n. From O. fraterna sp. n. it differs by the paler forebody, slightly broader and shorter elytra, and slightly broader median lobe of the aedeagus. From O. hlavaci sp. n. it differs by the paler coloration, sparser punctation of the head and the pronotum, and longer elytra. From O. smetanai sp. n. it differs by the paler elytra with the presence of wide spots in medioapical portions. From all these species, O. obliquesignata sp. n. can be distinguished by the different coloration of the elytra, slightly shorter parameres, details of the structure of the internal sac, and the shape of the female accessory sclerite. For additional detail see the key below.

Distribution. The new species is known only from the type locality in Qinling Shan, southern Shaanxi, China ( Fig. 17 ).

Etymology. The specific epithet is the Latine adjective obliquesignatus, - a, - um (with oblique marks). It refers to the presence of oblique darkened spots on the elytra.

Bionomics. Specimens were collected by sifting dead wood and mushrooms in deciduous forest with bamboo at elevation of 1990 m a.s.l.

Figures

FIGURE 17. Distribution of Omaliopsis in China: O. fraterna (circles), O. hlavaci (triangles), O. obliquesignata (black star), O. smetanai (diamonds).

FIGURES 1–4. Habitus of Omaliopsis: 1—O. fraterna (holotype), 2—O. hlavaci (holotype), 3—O. obliquesignata (holotype), 4—O. smetanai (holotype). Scale bars: 1.0 mm.

FIGURES 25–31. Omaliopsis obliquesignata: 25–aedeagus, parameral view, 26–aedeagus, lateral view, 27–male tergite VIII, 28–male sternite VIII, 29–female tergite VIII, 30–female sternite 8, 31–female accessory sclerite. Scale bar: 0.1 mm.