Nogunius infuscus, Jałoszyński, 2024

Jałoszyński, Paweł, 2024, Two new species of Nogunius Jałoszyński in Taiwan (Coleoptera: Staphylinidae: Scydmaeninae), Zootaxa 5437 (3), pp. 441-447 : 445-446

Nogunius infuscus sp. n.

( Figs 2, 4 , 9–12 , 13 )

Type material. Holotype: TAIWAN (Taitung Co.): ♁, three labels: “ 12.IV.2007 leg. S. Vit / Rd.no.11, W-Tulan, / envs. Frst. Moonlight-Inn / Taitung Co. TAIWAN merid. / frst. litter / (alt± 200 m.)” [white, printed]; “ Coll. S. Vit / MHNG - 2021” [white, printed]; “ NOGUNIUS / infuscus m. / P. Jałoszyński, 2024 / HOLOTYPUS” [red, printed] ( MHNG) . Paratypes (3 exx.): 2 ♁♁, same data as for holotype; 1 ♀, same data except for 420 m. Paratypes in MHNG and cPJ .

Diagnosis. Eyes in male large and strongly convex but in dorsal view much shorter than tempora; aedeagus in ventral view about four times as long as broad, with apical margin narrowly subtriangular and sharp-angled.

Description. Body of male ( Fig. 2 ) moderately slender, strongly convex, dark brown with distinctly infuscate elytra, but humeri and posterior region of adsutural area slightly lighter; appendages distinctly lighter than elytra, setae yellowish-brown; BL 0.74–0.81 mm.

Head ( Fig. 4 ) broadest at eyes, HL 0.16 mm, HW 0.16 mm; tempora in dorsal view much longer than eyes; vertex and frons confluent, together weakly convex; each eye large, strongly convex, in lateral view bean-shaped, with distinct posteromedian emargination. Punctures on vertex fine, inconspicuous; setae short, sparse and suberect; tempora and posterior margin of vertex densely covered with thick and long bristles. Antennae slender, AnL 0.30– 0.33 mm, antennomeres 1 and 2 each strongly elongate, 3–6 each about as long as broad, 7 and 8 indistinctly transverse, 9 distinctly larger than 8 and slightly transverse, 10 much longer and especially broader than 9, strongly transverse, 11 indistinctly narrower and slightly longer than 10, about as long as broad.

Pronotum subconical with rounded sides, broadest shortly in front of base; PL 0.20–0.23 mm, PW 0.20 mm. Anterior and posterior margins weakly convex, base with two pairs of small but distinct pits. Punctures on pronotal disc fine, inconspicuous; setae sparse, short, suberect; sides, especially posteriorly, with sparse, thick bristles.

Elytra together oval, broadest indistinctly in front of middle; EL 0.38–0.43 mm, EW 0.30–0.33 mm, EI 1.25– 1.33; humeral calli weakly elevated, basal impressions large, deep, nearly circular; apices separately rounded. Punctures inconspicuous; setae similar to those on pronotum, suberect.

Legs moderately long and slender, unmodified.

Hind wings long, functional.

Aedeagus ( Figs 9–12 ) elongate, in ventral view about four times as long as broad; AeL 0.11 mm; median lobe in ventral view indistinctly broadest in subapical region, with weakly concave sides, apical margin narrowly subtriangular and sharp-angled, pointed; endophallus in ventral view with a pair of small submedian comma-shaped sclerites; parameres slender, in lateral view largely straight, each with one long apical and one long subapical seta.

Female. In the only known female eyes are indistinctly smaller than those in males, so that head is not subquadrate, but slightly elongate. BL 0.78 mm; HL 0.16 mm, HW 0.15 mm, AnL 0.28 mm; PL 0.21 mm, PW 0.20 mm; EL 0.40 mm, EW 0.31 mm, EI 1.28.

Distribution. South-eastern Taiwan ( Fig. 13 ).

Etymology. The adjective infuscus (Lat. “dusky”) refers to the infuscate elytra. Remarks. Nogunius infuscus has the aedeagus conspicuously different than that in all remaining species ( Fig. 13 ). This species differs from the sympatric N. microtaiwanensis also in a larger body and a darker pigmentation, especially that on elytra.

Figures

FIGURE 13. Distribution of nominal Nogunius species, showing aedeagi for comparative purposes.

FIGURES 1–4. Nogunius microtaiwanensis sp. n. (1, 3) and N. infuscus (2, 4). Dorsal habitus of male (1, 2), and head in anterodorsal view (3, 4).

FIGURES 5–12. Nogunius microtaiwanensis sp. n. (5–8) and N. infuscus (9–12). Aedeagus in ventral (5, 7, 9, 11) and lateral (6, 8, 10, 12) views.