Paraneseuthia rugosa, Jałoszyński, 2020

Jałoszyński, Paweł, 2020, Four new Palaearctic, Australian and Oriental species of Paraneseuthia Franz (Coleoptera, Staphylinidae, Scydmaeninae), Zootaxa 4858 (2), pp. 231-240 : 234-235

Paraneseuthia rugosa sp. n.

( Figs 9–14 )

Type material. Holotype: PAPUA NEW GUINEA (Sandaun Province): ♂, two labels: “ PAPUA N.G. / Sandaun Prov. / N Mianmin, / 1100m, sifted, / 20.5.98 leg. A.Riedel ” [white, printed]; “ PARANESEUTHIA / rugosa m. / P. Jałoszyński, 2020 / HOLOTYPUS ” [red, printed] ( MHNG) . Paratype: 1 ♂, same data as for holotype ( MHNG) .

Diagnosis. Body conspicuously large (BL> 1.5 mm) and stout, covered with long and suberect setae; eyes extremely large and convex; head in males with transverse wrinkles between eyes, male protibia and metaventrite unmodified; aedeagus conspicuously slender, with nearly symmetrical median lobe bearing two pairs of elongate laterodistal projections, of which dorsal pair is directed distoventrad, with oval diaphragm situated in sub-basal region.

Description. Body of male ( Fig. 9 ) stout and strongly convex, light brown, setae yellowish; BL 1.55 mm.

Head ( Figs 9–10 ) broadest at strikingly large and strongly convex, coarsely faceted eyes, HL 0.25 mm, HW 0.33–0.35 mm; vertex and frons confluent and flattened, between eyes with transverse arcuate wrinkles; supraantennal tubercles indistinct, frontoclypeal region in front of eyes strongly convex at middle. Punctures on vertex and frons inconspicuous, setae sparse and recumbent. Antennae ( Fig. 9 ) short but slender, with distinctly delimited trimerous club, AnL 0.70–0.73 mm, antennomeres I–VII each elongate, VIII–X each about as long as broad, XI distinctly broader than X, about as long as IX–X together, nearly twice as long as broad.

Pronotum ( Fig. 9 ) nearly semicircular with all margins rounded, broadest slightly behind middle; PL 0.38 mm, PW 0.55–0.56 mm; posterior corners obtuse-angled and blunt, anterior corners not marked; pronotal base with barely discernible, tiny and diffuse median pit and two pairs of small but distinct lateral pits, of which the lateralmost pair is developed as elongate impressions. Punctures on pronotal disc fine and inconspicuous; setae long, sparse and suberect.

Elytra ( Fig. 9 ) together oval, broadest between middle and anterior third and weakly narrowing posterad, evenly, strongly convex; EL 0.93 mm, EW 0.75 mm, EI 1.23; humeral calli prominent, elongate; basal impressions lacking; apices separately rounded. Punctures on elytra inconspicuous, small and diffuse; setae long, moderately dense and suberect. Hind wings present.

Legs moderately long and slender; unmodified, mesotibiae indistinctly recurved.

Aedeagus ( Figs 11–14 ) conspicuously slender, AeL 0.33 mm; median lobe in ventral view nearly symmetrical; apex with two pairs of elongate projections, of which the dorsal pair is longer and directed distoventrad; diaphragm oval and situated in sub-basal region; parameres slender, each with 1–2 apical setae.

Female. Unknown.

Distribution. West-northern Papua New Guinea.

Etymology. The name rugosa (Latin “wrinkled”) refers to the transverse wrinkles on the frons between eyes.

Remarks. Among all known species of Paraneseuthia , the sympatric P. rugosa and P. levigata Jałoszyński, 2010 are distinct in having extremely elongate aedeagi. These species are similar to each other, and their aedeagi in ventral view are nearly identical. Differences can be seen in the lateral view: in P. rugosa the apical projections are curved ventrad, whereas in P. levigata slightly dorsad. The ventral apical projections in P. rugosa are also much longer than those in P. levigata . Differences in external structures allow for unambiguous identification of both species. Paraneseuthia rugosa has larger adults (1.55 mm, vs. 1.28 in P. levigata ), with antennomere X about as long as broad, whereas in P. levigata antennomere X is strongly transverse. But first of all, males of these species differ in modifications of the frons. In P. rugosa , the frons between eyes is covered with transverse wrinkles, with their lateral portions bent posterad (wrinkles behind middle) and anterad (wrinkles in front of middle). In P. levigata , the frons bears C-shaped ocular grooves along mesal margins of eyes, and an anteromedian inversely U-shaped groove that separates the inter-antennal region from frons between eyes (illustrated by Jałoszyński (2010)).

Figures

FIGURES 9–14. Paraneseuthia rugosa sp. n., male. Dorsal habitus (9); head in dorsal view (10); aedeagus in ventral (11, 13) and lateral (12, 14) views.