Omaliopsis propinqua, Shavrin, 2023

Shavrin, Alexey V., 2023, Three new species of Omaliopsis Jeannel, 1940 and Omalium Gravenhorst, 1802 from Taiwan (Coleoptera: Staphylinidae: Omaliinae, Omaliini), Zootaxa 5244 (2), pp. 173-181 : 174-176

Omaliopsis propinqua sp.n.

( Figs. 1–9 )

Type material examined: Holotype ♁ (dissected; left protarsus missing): ‘ TAIWAN Nantou | Hsien, Houhuanshan | Kuenyang 3050m | 27.IV.1990 | A. Smetana [T29]’ <printed>, ‘HOLOTYPE | Omaliopsis | propinqua sp.n. | Shavrin A.V. des. 2023’ <red, printed> ( CNC).

Paratype ♀ ( Fig. 1 ; dissected): ‘ TAIWAN, Ilan Hsien | Taipingshan | 1820m 15.VII.[19]93 | A.Smetana [T153]’ <printed>, ‘PARATYPE | Omaliopsis | propinqua sp.n. | Shavrin A.V. des. 2023’ <red, printed> ( CNC).

Description. Measurements (n=2): HW: 0.60–0.61; HL: 0.40; AL (holotype): 0.87; OL: 0.12–0.14; TM: 0.05–0.06; PL: 0.52–0.57; PW: 0.77; ESL: 0.92–0.96; EW: 0.97; AW: 0.92–0.93; MTbL (holotype): 0.50; MTrL (holotype): 0.17 (MTrL 1–4: 0.07; MTrL 5: 0.10); AedL: 0.57; TL: 3.05–3.50 (holotype).

Habitus as in Fig. 1 . Forebody reddish-brown, with slightly darker head, mediobasal and apical portions of pronotum; antennomeres 6–11 brown; mouthparts, antennomeres 1–4, legs and abdomen yellow-brown (paratergites and apical segments of abdomen of paratype slightly paler); tarsi yellowish. Punctation of head irregular, moderately dense and deep, laterobasal portions with markedly finer and sparser punctation; neck with moderately sparse and fine punctation; punctation of pronotum distinctly sparser than that on head, slightly larger and deeper in mediobasal portion and finer in middle, middle portion between longitudinal depressions without punctures; elytra with very dense punctation, larger and deeper than that on pronotum, denser and coarser in mediobasal portion, finer along suture; abdominal tergites with dense and very fine punctation. Forebody glossy; anterior portion of head with dense and transverse microreticulation, anteriomedian depression with dense and coarse, subdiagonal meshes, middle portion with dense elongate microsculpture; neck with very dense isodiametric sculpture; pronotum with dense and transverse microreticulation; scutellum with fine isodiametric meshes; abdominal tergites with distinct, dense and transverse microsculpture. Anterior and lateral portions of head with several long setae; lateral margins of pronotum with four to six moderately short setae; lateral margins and disc of each elytron with very sparse and small semierect setae; abdominal tergites with several short setae on lateral margins of paratergites; anterior and posterior margins of pronotum and posterior margins of each elytron with row of very short cuticular fringe.

Head 1.5 times as broad as long, with slightly elevated middle portion, with moderately wide and deep anteriomedian depressions and with indistinct semicircular impression in front of ocelli (paratype); temples short, gradually narrowing toward neck, without postocular ridges; anteocellar foveae (grooves in front of ocelli) very short and deep. Eyes large and convex. Ocelli large and convex, located slightly behind level of posterior margins of eyes, distance between ocelli slightly shorter than distance between ocellus and posterior margin of eye. Maxillary palpi moderately long, palpomere 4 (apical) about four times as long as small and slightly transverse penultimate segment. Antenna reaching middle of pronotum when reclined, antennomeres 6–9 transverse, apical six antennomeres with strong pubescence; basal antennomere wide, about two and a half times as long as broad, antennomere 2 oblong, distinctly narrower than basal antennomere, 3 distinctly narrower than 2, 4–5 small, about as long as broad, markedly shorter than 3, 6 distinctly broader and slightly longer than 5, 7–9 slighttly broader than 6, 10 slightly longer than 9, apical antennomere about 1.4 times as long as 10, from apical third gradually narrowed toward rounded apex.

Pronotum slightly convex, 1.3–1.4 times as broad as long, 1.2 times as broad as head, widest about in middle, gradually rounded anteriad and slightly narrowing posteriad toward obtuse posterior angles; lateral margins narrowly marginated; surface of disc with two distinct, long and wide longitudinal depressions, laterobasal portions deeply impressed.

Elytra slightly longer than broad, 1.6–1.7 times as long as pronotum, somewhat parallel-sided in anterior half and middle, and indistinctly broadened in posterior portion; lateral margins marginated; hind margins straight. Wings fully developed.

Metatarsi about three times shorter than metatibia.

Abdomen convex, slightly narrower than elytra, with two small oval wing-folding patches (tomentose spots) in middle of abdominal tergite IV and indistinct narrow palisade fringe on apical margin of abdominal tergite VII.

Male. Posterior margin of abdominal tergite VIII slightly emarginate ( Fig. 2 ). Medioapical portion of sternite VIII with two very small protrusions; posterior margin deeply and widely emarginate ( Fig. 3 ). Aedeagus with wide basal portion, slightly narrowed apicad toward middle and from about apical third part sligthly broadened apicad toward widely rounded apex; apical margin of median lobe with small subtriangular notch in middle; parameres narrow, slightly not reaching apex of median lobe, with three apical and one preapical short setae; internal sac long and wide, with two mediobasal fields of elongate thorns and two sclerotized structures in basal portion ( Fig. 4 ). Lateral aspect of the aedeagus as in Fig. 5 .

Female. Posterior margins of abdominal tergite VIII ( Fig. 6 ) and sternite VIII ( Fig. 7 ) truncate. Female genital segment as in Fig. 8 ; accessory sclerite with wide basal portion and elongate median part, from middle gradually narrowing apicad. Spermatheca as in Fig. 9 .

Comparative notes. Based on the general shape of the body and the aedeagus, O. propinqua sp.n. is similar to O. musaphila ( Rougemont, 2017) , known from China ( Rougemont 2017, Shavrin 2019), from which it can be distinguished by the paler coloration, the shape of the apical portion of the median lobe (distinctly bilobed in O. musaphila ), and details of the morphology of the internal sac, if compared with Fig. 4 and Fig. 18 in Shavrin (2019). Regarding the shape of the apical portion of the median lobe with the presence of the small notch in the middle (if compare Fig. 4 and Fig. 26 in Thayer (2003)), O. propinqua sp.n. is somewhat similar to O. ectopia Thayer, 2003 , known from southwestern USA and México, from which it can be distinguished by the paler coloration of the larger body, slightly narrower pronotum, shorter elytra and details of the morphology of the aedeagus.

Distribution. The new species is known from two locations in Nantou Hsien and Ilan Hsien, central and north Taiwan.

Bionomics. Specimens were taken by sifting forest floor litter at elevations from 1820 to 3050 m a.s.l.

Etymology. The specific epithet is the Latin adjective propinquus, - a, - um (related). It alludes to the similarity of the new species to O. musaphila .

Figures

FIGURES 1–9. Omaliopsis propinqua: 1–habitus (paratype), 2–male tergite VIII (dorsal view), 3–male sternite VIII (ventral view), 4–aedeagus (parameral view), 5–aedeagus (lateral view), 6–female tergite VIII (dorsal view), 7–female sternite VIII (ventral view), 8–female genital segment, 9–spermatheca. Scale bars: 1.0 mm (Fig. 1), 0.1 mm (Figs. 2–9).

FIGURES 18–25. Omalium latissimum: 18–habitus (holotype), 19–male tergite VIII (dorsal view), 20–male sternite VIII (ventral view), 21–aedeagus (parameral view), 22–aedeagus (lateral view), 23–female tergite VIII (dorsal view), 24–female sternite VIII (ventral view), 25–female genital segment. Scale bars: 0.1 mm.