Nipponophloeostiba hornabrooki, Shavrin, 2024

Shavrin, Alexey V., 2024, Twenty-one new species of Omaliini from the Papuan Region (Coleoptera: Staphylinidae: Omaliinae), with diagnostic and faunistic notes on some species of the genus Paraphloeostiba Steel, 1960, Zootaxa 5424 (3), pp. 251-307 : 253-256

Nipponophloeostiba hornabrooki sp. n.

( Figs 1 , 7–11 )

Type material. Holotype ♂ ( Fig. 1 ; specimen without left middle leg and right elytron; dissected): ‘ NEW GUINEA | Okapa, | 28.V.1965 ’ <printed>, ‘ R. Hornabrook | BM 1970-232.’ <printed>, ‘ HOLOTYPE | Nipponophloeostiba | hornabrooki sp. n. | Shavrin A. V. des. 2024’ <red, printed> ( BMNH).

Description. Measurements: HW: 0.47; HL: 0.30; OL: 0.15; TL: 0.05; AL: 0.61; PL: 0.40; PWmax: 0.57; PWmin: 0.40; ESL: 0.62; EW: 0.60; MTbL: 0.30; MTrL: 0.15 (MTrL 1–4: 0.05; MTrL 5: 0.10); AW: 0.60; AedL: 0.27; BL: 2.34.

Habitus as in Fig. 1 . Head, pronotum and abdomen reddish-brown; elytra yellow-brown, with reddish apical portion; antennomeres 6–11 brown; mouthparts, antennomeres 1–5, intersegmental membranes between abdominal tergites and legs yellowish. Head with sparse and fine punctation, slightly denser in middle; neck with several very fine punctures in middle; pronotum with very fine punctation, similar to that in head, but distinctly denser, finer in lateral and sparser and finer in mediobasal portions; scutellum without punctures; elytra with moderately dense punctation, slightly deeper than that in pronotum, finer and sparser around scutellum and along suture; abdomen without visible punctation. Head with dense and coarse microsculpture, transverse in apical, longitudinal in middle and isodiametric in lateral portions; neck with very fine transverse microreticulation; pronotum with very dense isodiametric microsculpture, longitudinal in mediobasal and transverse in laterobasal portions; scutellum with dense and coarse transverse meshes; abdomen with dense and coarse microreticulation, transverse in abdominal tergites III–V and isodiametric in VI–VIII.

Head 1.5 times as broad as long, with moderately wide and shallow anteriomedian depressions with distinct narrow elevated carina along outer margin of each depression, reaching level of apical third of eyes; anteocellar foveae (grooves in front of ocelli) deep and long, linear, extending about level of middle length of eyes; basal margin straight; posterior portions between ocelli and temples with narrow, distinctly elevated straight carina, reaching laterobasal margin of head; each basal margin of infraorbital portion near carina with small oval depression, with setae on bottom of it; temples (postocular parts) three times shorter than longitudinal length of eyes, convex, not expanded laterad. Eyes moderately large, convex. Ocelli moderately large, located very close to neck constriction, distance between ocelli slightly shorter than distance between ocellus and posterior margin of eye. Maxillary palpi long; preapical palpomere indistinctly longer than wide; apical palpomere narrow, about 1.3 times as long as preapical segment, from apical third gradually narrowed toward acute apex. Antennae almost reaching basal margin of pronotum when reclined; antennomeres 6–10 distinctly transverse; basal antennomere moderately wide, slightly more than twice as long as broad, antennomere 2 distinctly shorter and slightly narrower than basal antennomere, 3 slightly longer and narrower than 2, 4 twice shorter than 3, 5 about as long as wide, slightly broader than 4, 6 distinctly broader than 5, 7–9 slightly longer and distinctly broader than 6, 10 indistinctly longer than 9, apical antennomere about twice longer than 10, from about middle gradually narrowed towar subacute apex.

Pronotum transverse, 1.4 times as broad as long, slightly broader than head, widest in preapical portion, strongly narrowed posteriad toward obtuse hind angles; apical angles widely rounded; anterior margin slightly concave in middle, with two distinct, relatively small elevated tubercles at level of small oval depression near carina of head; posterior margin rounded; median part without longitudinal band, only with short and narrow trace of it in mediobasal portion; lateral portions narrowly bordered, with slightly impressed laterobasal portions.

Elytra slightly longer than broad, reaching basal margin of abdominal tergite III, 1.5 times as long as pronotum, somewhat parallelsided, slightly concave in middle, with straight apical margins. Hind wings fully developed.

Metatarsus twice as long as metatibia.

Abdomen indistinctly widened toward abdominal tergite V, about as broad as elytra, with two small oval wing-folding patches (tomentose spots) in middle of abdominal tergite IV and distinct narrow palisade fringe at apical margin of abdominal tergite VII.

Male. Posterior margin of abdominal tergite VIII somewhat straight ( Fig. 9 ). Posterior margin of abdominal sternite VIII widely sinuate ( Fig. 10 ).Aedeagus short, with wide median lobe and very wide truncate apex; parameres moderately narrow, reaching apex of median lobe, slightly widened in apical portions, each with lateral obtuse tooth on inner margin of preapical portion, with three to four moderarely short apical setae and three short setae along inner margin of each paramere; internal sac short and relatively wide, with long flagellum, starting from basal portion and reaching apical third of median lobe ( Fig. 7 ). Lateral aspect of the aedeagus as in Fig. 8 .

Female unknown.

Comparative notes. Based on the body size, the shape of postocular portions of the head slightly broader than pronotum and relatively short elytra, slightly broader than pronotum, N. hornabrooki sp. n. is similar to N. explanata Shavrin, 2023 , recently described from Bali ( Shavrin 2023a). It can be distinguished from it by the longer temples, paler elytra and the different morphology of the aedeagus. From all species of the genus it differs by the broader median lobe and internal structure of the aedeagus.

Distribution. Nipponophloeostiba hornabrooki sp. n. is known only from the type locality in central part of Papua New Guinea ( Fig. 11 ).

Etymology. The species is named after R. Hornabrook, the collector ot the type material.

Bionomics. The detailed bionomical data are unknown.

Figures

FIGURE 11. Distribution of Nipponophloeostiba: N. verrucifera (circles), N. thayeri (triangle), N. longilobata (square), N. explanata (diamond), N. hornabrooki (star).

FIGURES 1–6. Habitus of Omaliini: 1–Nipponophloeostiba hornabrooki (holotype), 2–Paraphloeostiba assimile (holotype), 3–P. atramentaria (holotype), 4–P. attenuata (paratype), 5–P. barclayi (paratype), 6–P. betlephila (holotype). Scale bars: 1.0 mm.

FIGURES 7–10. Nipponophloeostiba hornabrooki (holotype): 7–aedeagus, parameral view, 8–aedeagus, lateral view, 9–male abdominal tergite VIII, 10–male abdominal sternite VIII. Scale bar: 0.1 mm.