Phloeostiba assingi, Shavrin, 2020

Shavrin, Alexey V., 2020, New species and records of Paraphloeostiba Steel, 1960 from China and Laos and descriptions of four new species of related genera (Coleoptera: Staphylinidae Omaliinae: Omaliini), Zootaxa 4890 (3), pp. 301-329 : 324-327

Phloeostiba assingi sp.n.

( Figs. 60–66 )

Type material examined: Holotype Ƌ: ‘LAOS—Houa Phan prov., | Phu Phan Mt. , 20°12’N, | 104°01’E, ca. 1750 m, | 17.V.–3.VI.2007, leg. Vit Kuban’ <printed>, ‘ HOLOTYPE | Phloeostiba | assingi sp. n. | Shavrin A. V. des. 2020’ <red, printed> ( NHMB).

Paratypes (10 specimens): 3 ƋƋ (two specimens dissected), 7 ♀♀ (two specimens dissected): same data as the holotype, ‘ PARATYPE | Phloeostiba | assingi sp.n. | Shavrin A. V. des. 2020’ (2 ƋƋ, 2 ♀♀: CS; 1 ƋƋ, 5 ♀♀: CA).

Description. Measurements (n=9): HW: 0.46–0.50; HL: 0.25–0.31; AL (holotype): 0.53; OL: 0.14–0.17; PL: 0.33–0.40; PW: 0.53–0.60; ESL: 0.54–0.65; EW: 0.65–0.67; AW: 0.57–0.61; MTbL (holotype): 0.30; MTrL (holotype): 0.17 (MTrL 1–4: 0.05; MTrL 5: 0.12); AedL: 0.32–0.35; TL: 2.53–2.87 (holotype: 2.80).

Head, antennomeres 3–11, pronotum, and abdomen brown to reddish-brown (some paratypes with paler lateral and basal portions of pronotum); preapical maxillary palpomeres and elytra yellow-brown, with darker parascutellar portion; mouthparts, apical maxillary palpomere, antennomeres 1–2, intersegmental membranes of abdomen, and legs yellow. Head with sparse, fine punctures, denser in middle portion, and sparser between ocelli and posterior portions of head between ocelli and dorsolateral margins of eyes; mediobasal portion of neck with several very fine punctures; pronotum with moderately dense and fine punctures, sparser in medioapical, mediobasal, and laterobasal portions; scutellum without punctures; elytra with punctation similar to that of pronotum, but distinctly denser and finer in basal portion; abdominal tergites with indistinct, fine and sparse punctation. Head with dense and moderately coarse punctation: transverse in apical portion, transverse or isodiametric in middle and in infraorbital ridges; middle portion of neck with transverse and/or longitudinal meshes; pronotum with microsculpture similar to that of head: transverse in medioapical and mediobasal, isodiametric in middle, and longitudinal in lateral portions; scutellum with narrow and dense transverse meshes; surface of each elytron between punctures with net-like, isodiametric and/or longitudinal microreticulation; abdomen with dense and moderately coarse, transverse microsculpture.

Head indistinctly convex in middle and posterior portions of infraorbital ridges, with narrow, diagonal postantennal impressions (indistinct in some specimens) reaching level of apical third of eyes, 1.6–1.8 times as broad as long, with long, narrow and deep anteocellar foveae reaching middle of eye; postocular parts sharply rounded toward neck, without postocular carina. Ocelli small, located very close to posterior constriction, distance between ocelli about 1.3 times as long as distance between ocellus and posterior margin of eye. Neck separated from head by moderately narrow, but very deep constriction. Apical palpomere of maxillary palpi about 1.3 times as long as penultimate palpomere. Antennae short, reaching basal margin of pronotum when reclined; basal antennomere slightly less than twice as long as broad, antennomere 2 suboval, slightly longer than wide, 3 distinctly narrower and about as long as 2, 4 very small, about as long as wide, 5 slightly transverse, distinctly wider than 4, 6–10 progressively widened, covered by dense pubescence, 6 strongly transverse, about as broad as 5, 7 wider than 6, 8–9 slightly wider than 7, and 10 slightly wider than 9, apical antennomere slightly more than twice as long as 10, from about middle narrowed towards the rounded apex.

Pronotum flattened, 1.5–1.6 times as broad as long, 1.1–1.2 times as broad as head, widest in middle, gradually narrowing towards the rounded anterior angles and moderately sharply narrowed posteriad; laterobasal margins slightly concave in front of the obtuse posterior angles; anterior margin straight or slightly concave, about as long as the rounded posterior margin, with two distinct, moderately large and deep oval impressions at level of lateral margins of neck; median part with indistinct, very narrow longitudinal impunctate band; lateral portions narrowly bordered and flattened at margins, laterobasal portions impressed and slightly reflexed.

Elytra about as broad as long or slightly broader, 1.6 times as long as pronotum, slightly widened apicad, indistinctly concave at lateral margins; posterior margin straight.

Metatarsi 1.7 times as long as metatibia.

Abdomen slightly narrower than combined width of elytra, with two round wing-folding patches in middle of abdominal tergite IV, with narrow palisade fringe at apical margin of abdominal tergite VII.

Male. Posterior margin of abdominal tergite VIII rounded ( Fig. 62 ). Posterior margin of abdominal sternite VIII deeply concave ( Fig. 63 ). Aedeagus suboval, with wide basal portion, narrowed apically, with moderately wide median lobe, rounded apically and with two large, rounded protrusions in latero-apical third ( Fig. 60 ); parameres moderately narrow, long, but not extending beyond apex of median lobe, with three long apical and several setae on inner edge of each paramere; internal sac short, with two long, sclerotized structures in middle and one in basal portion. Aedeagus laterally as in Fig. 61 .

Female. Posterior margins of abdominal tergite VIII ( Fig. 64 ) and sternite VIII ( Fig. 65 ) rounded. Female accessory sclerite subtriangular ( Fig. 66 ). Spermatheca not found.

Comparative notes. Regarding body length, coloration, habitus, and the general shape of the aedeagus, P. assingi sp.n. is similar to the Palaearctic P. plana (Paykull, 1792) , from which it differs by somewhat paler and shorter elytra, a wider apical portion of the median lobe of the aedeagus and of the parameres, larger latero-apical protrusions on each side of the apical third of the median lobe, and the completely different shape of the female genital segment.

Distribution. The new species is known only from the type locality in Phu Phan mountain range, northern Laos.

Bionomics. Specimens were collected on the wing, most likely with a Malaise trap, at an elevation of 1750 m a.s.l.

Etymology. Patronymic, the species is named to honour my colleague Volker Assing ( Germany).

Figures

FIGURES 60–61. Aedeagus of Phloeostiba assingi (paratype): 60—parameral view, 61—lateral view. Scale bar: 0.1 mm.

FIGURES 62–66. Abdominal segments of Phloeostiba assingi: 62—male tergite VIII (dorsal view), 63—male sternite VIII (ventral view), 64—female tergite VIII (dorsal view), 65—female sternite VIII (ventral view), 66—female accessory sclerite. Scale bar: 0.1 mm.