Paraphloeostiba assimile, 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 : 257-259

Paraphloeostiba assimile sp. n.

( Figs 2 , 12–15 )

Type material. Holotype ♂ ( Fig. 2 ; dissected): ‘ NEW GUINEA | Karimui, | 13.III.1966 ’ <printed>,‘ R. Hornabrook | BM 1970-232.’ <printed>, ‘ HOLOTYPE | Paraphloeostiba | assimile sp. n. | Shavrin A. V. des. 2024’ <red, printed> ( BMNH).

Description. Measurements: HW: 0.36; HL: 0.21; OL: 0.11; AL: 0.55; PL: 0.27; PWmax: 0.50; PWmin: 0.43; ESL: 0.50; EW: 0.56; MTbL: 0.26; MTrL: 0.13 (MTrL 1–4: 0.03; MTrL 5: 0.10); AW: 0.64; AedL: 0.25; BL: 1.76.

Habitus as in Fig. 2 . Body yellow-brown, with reddish-brown apical portions of elytra; antennomeres 5–11 brown; mouthparts, antennomeres 1–4 and legs yellow. Head and neck without visible punctation; pronotum with indistinct and sparse fine punctation, slightly more visible in lateral portions; scutellum without punctures; elytra with fine indistinct punctation, slightly larger than that on pronotum, more indistinct in middle; abdominal tergites with indistinct fine and sparse punctation. Head with very dense and coarse microsculpture, transverse on vertex and isodiametric in middle portion; neck with fine transverse meshes; pronotum with very dense isodiametric microreticulation similar to that in middle portion of head; scutellum with fine transverse microreticulation; microsculpture of elytra very dense, isodiametric, similar to that in pronotum, slightly transverse in mediobasal portion; abdominal tergites with dense isodiametric microsculpture.

Head indistinctly elevated in middle, with shallow wide anteriomedian depressions, 1.7 times as broad as long, with short and deep anteocellar foveae, reaching level of posterior third length of eyes; postocular carina indistinct, acute, located very close to posterior margin of eyes. Ocelli moderately large, located slightly below level of posterior margins of eyes; distance between ocelli 1.4 times larger than distance between ocellus and posterior margin of eyes. Apical maxillary palpomere very narrow, about 1.7 times as long as preapical segment. Antenna reaching basal margin of pronotum when reclined, with distinctly transverse antennomeres 6–10; basal antennomere about twice as long as broad, antennomere 2 distinctly shorter and slightly narrower than basal antennomere, 3 distinctly narrower than 2, 4 about as long as wide, about twice shorter than 3, 5 slightly shorter than 4, 6 slightly longer and distinctly broader than 5, 7–9 slightly longer and distinctly broader than 6, 10 slightly longer than 9, apical antennomere about twice as long as 10, from about middle gradually narrowed apicad toward rounded apex.

Pronotum slightly convex, transverse, 1.8 times as broad as long, 1.3 times as broad as head, widest in middle, gradually narrowed both anteriad and posteriad; anterior angles widely rounded, not protruded anteriad; posterior angles obtuse; anterior margin slightly concave in middle, slightly shorter than rounded posterior margin; middle portion without impressions; laterobasal impressions moderately wide and deep.

Elytra slightly broader than long, 1.8 times as long as pronotum, slightly broadened posteriad; posterior margin straight.

Metatarsi twice shorter than metatibia.

Abdomen slightly broader than elytra, with two very small and round wing-folding patches in middle of abdominal tergite IV; apical margin of abdominal tergite VII with narrow palisade fringe.

Male. Posterior margin of abdominal tergite VIII truncate ( Fig. 13 ). Posterior margin of abdominal sternite VIII widely and deeply concave ( Fig. 14 ). Aedeagus with very wide basal portion, gradually narrowed toward relatively wide median lobe with rounded apex; parameres significantly longer than apex of median lobe, from middle significantly widened apically toward rounded apices, each with four to five moderately short setae, with three short setae on inner margin in about middle; internal sac wide and moderately long, with several elongate sclerotized structures in middle ( Fig. 12 ). Lateral aspect of the aedeagus as in Fig. 13 .

Female unknown.

Comparative notes. Based on the very broad median lobe and apical portions of the parameres, P. assimile sp. n. is similar to P. celebensis Steel, 1960 ( Indonesia: Sulawesi), P. papuana , P. penelopeae sp. n., P. rufula sp. n., and P. tonkinesis (Cameron, 1940) , known from Vietnam and Singapore ( Steel 1960). It can be distinguished from all these species by the following morphological features:

from P. celebensis by the absence of visible punctation on the head;

from P. papuana by the absence of punctation on the head and slightly narrower elytra;

from P. penelopeae sp. n. by the slightly narrower pronotum;

from P. rufula sp. n. by the smaller body, the darker elytra and more transverse pronotum;

from P. tonkinesis by the longer body, the absence of punctation on the head and the presence of traces of longitudinal impressions in the middle of the pronotum.

From all these species, P. assimile sp. n. can be distinguished by the longer parameres, and other details of the external and internal structure of the aedeagus.

Distribution. Paraphloeostiba assimile sp. n. is known only from the type locality in central part of Papua New Guinea.

Etymology. The specific epithet is the Latin assimilis, - e (similar). It alludes to the similarity of the new species with some other relative species.

Bionomics. The detailed bionomical data are unknown.

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 12–15. Paraphloeostiba assimile (holotype): 12–aedeagus, parameral view, 13–aedeagus, lateral view, 14–male abdominal tergite VIII, 15–male abdominal sternite VIII. Scale bar: 0.1 mm.