Paraphloeostiba attenuata, 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 : 261-263

Paraphloeostiba attenuata sp. n.

( Figs 4 , 20–25 )

Type material. Holotype ♂ ( Fig. 4 ; underside of the card with handwritten number ‘65’): ‘ NEW GUINEA | Okapa, | 27.VI.1965 ’ <printed>, ‘ R. Hornabrook | BM 1970-232.’ <printed>, ‘ HOLOTYPE | Paraphloeostiba | attenuata sp. n. | Shavrin A. V. des. 2024’ <red, printed> ( BMNH).

Paratypes: 1 ♀ (dissected): same data as the holotype ( BMNH); 1 ♂ (dissected): ‘ NEW GUINEA | Okapa, 23. V.1965, | cow dung and be- | ating’ <printed>, ‘ R. Hornabrook | BM 1970-232.’ <printed> ( BMNH); 1 ♀ (underside of the card with handwritten number ‘64’): ‘ NEW GUINEA | Okapa, 16. VI.1965, | flying in daylight’ <printed>, ‘ R. Hornabrook | BM 1970-232.’ <printed> ( BMNH); 1 ♂ (right antennomeres 3–11 missing; underside of the card with handwritten number ‘85’), 2 ♀♀ (one specimen without left antenna; underside of the card with handwritten number ‘85’): ‘ NEW GUINEA | Okapa, | 27.VIII.1965, | forest litter’ <printed>, ‘ R. Hornabrook | BM 1970-232.’ <printed> ( BMNH); 1 ♀ (underside of the card with handwritten number ‘170’): ‘ NEW GUINEA Go- | roka, | 28.III.1971 ’ <printed>, ‘ R. Hornabrook | BM 1970-232.’ <printed> ( BMNH); 1 ♂ (underside of the card with handwritten number ‘86’): ‘ NEW GUINEA | Lae, | 25.VIII.1965 ’ <printed>, ‘ R. Hornabrook | BM 1970-232.’ <printed> ( BMNH). All paratypes with additional red printed label: ‘ PARATYPE | Paraphloeostiba | attenuata sp. n. | Shavrin A. V. des. 2024’.

Description. Measurements (n=9): HW: 0.38–0.42; HL: 0.22–0.35; OL: 0.11–0.15; AL (holotype): 0.51; PL: 0.27–0.36; PWmax: 0.48–0.62; PWmin: 0.43–0.57; ESL: 0.37–0.47; EW: 0.72–0.76; MTbL (holotype): 0.27; MTrL (holotype): 0.18 (MTrL 1–4: 0.04; MTrL 5: 0.14); AW: 0.66–0.75; AedL: 0.30; BL: 1.58–2.00 (holotype: 1.92).

Habitus as in Fig. 4 . Body glossy, yellowish-brown to reddish brown, with paler elytra and slightly darkened lateroapical and posterior portions of elytra; antennomeres 6–11 or 7–11 brown; mouthparts, antennomeres 1–5 or 1–6 and legs yellow. Head without or with indistinct, very fine and sparse punctation, slightly denser and larger in middle in two paratypes; neck without visible punctures; pronotum with fine and sparse punctation, finer and more indistinct in middle (one paratype without visible punctation in middle); scutellum without punctures; elytra with moderately dense punctation, distinctly larger than that in pronotum, sparser and finer around scutellum and along suture; abdominal tergites with indistinct or distinct sparse and fine punctation, finer and sparser in middle. Head with dense microsculpture, usually coarser in middle; pronotum with dense isodiametric microsculpture similar to that in middle portion of head; microreticulation of elytra dense, similar to that in pronotum; abdominal tergites with fine and dense isodimaetric microreticulation.

Head with distinct, shallow or moderately deep and wide anteriomedian depressions, 1.2–1.7 times as broad as long, with very short and deep anteocellar foveae about as long as broad of each ocellus; middle portion between ocelli in one paratype semicircularly depressed; postocular carina distinct, acute. Ocelli small, located slightly above or about at level of posterior margins of eyes; distance between ocelli distinctly larger than distance between ocellus and posterior margin of eyes. Apical maxillary palpomere 1.5–1.7 times as long as preapical segment. Antennomere 3 about as long as or slightly shorter and distinctly narrower than 2, 4 about twice shorter than 3, 5 slightly shorter than 4, 6 slightly longer and distinctly broader than 5, 7–8 distinctly broader than 6, 9–10 slightly longer than 8, apical antennomere slightly more than twice as long as 10, from middle gradually narrowed toward subacute apex.

Pronotum 1.7 times as broad as long, 1.2–1.4 times as broad as head, widest in or slightly behind middle, significantly more narrowed posteriad than anteriad; laterobasal portions widely concave, sometimes with subparallel laterobasal margins in front of obtuse hind angles; middle portion without or with very indistinct wide and long median impressons; lateral impressions wide and deep, distinctly broader in laterobasal portions.

Elytra 1.6–1.9 times as broad as long, 1.3 times as long as pronotum, with narrowly impressed lateral margins.

Metatarsi 1.5 times as long as metatibia.

Male. Posterior margin of abdominal tergite VIII straight ( Fig. 22 ). Posterior margin of abdominal sternite VIII concave ( Fig. 23 ). Aedeagus with very wide basal portion, gradually narrowed toward small rounded apex; parameres moderately narrow, reaching apex of median lobe, slightly broadened apically, with rounded apices, each with four moderately long apical setae and two short setae in middle of inner margin; internal sac wide and short, with three elongate sclerotized structures in basal portion ( Fig. 20 ). Lateral aspect of the aedeagus as in Fig. 21 .

Female. Posterior margins of abdominal tergite VIII ( Fig. 24 ) and abdominal sternite VIII ( Fig. 25 ) rounded. Female accessory sclerite and spermatheca not recognized.

Comparative notes. Based on the general shape of the body with the presence of indistinct longitudinal impressions, the length and the coloration of the body, and the general shape of the aedeagus, P. attenuata sp. n. is similar to P. gracillima Shavrin, 2022 , recently described from Thailand ( Shavrin 2022). The new species can be distinguished from it by the concave laterobasal margins of the pronotum in front of hind angles, finer punctation of the head and the pronotum, the longer elytra, slightly broader apical portion of the median lobe and narrower apical portions of the parameres.

Distribution. Paraphloeostiba attenuata sp. n. is known from two localities in central part of Papua New Guinea (Fig. x).

Etymology. The specific epithet is the Latin attenuatus, - a, - um (narrowed to a point). It alludes to the general shape of the aedeagus.

Bionomics. Paratypes were collected in cow dung, forest litter or in flight.

Figures

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 20–25. Paraphloeostiba attenuata (paratypes): 20–aedeagus, parameral view, 21–aedeagus, lateral view, 22–male abdominal tergite VIII, 23–male abdominal sternite VIII, 24–female abdominal tergite VIII, 25–female abdominal sternite VIII. Scale bar: 0.1 mm.