Hlavaciellus carinatus, Jałoszyński, 2021

Jałoszyński, Paweł, 2021, Six new species of the Oriental genus Hlavaciellus Jałoszyński (Coleoptera Staphylinidae, Scydmaeninae), Zootaxa 4966 (1), pp. 1-15 : 4-5

Hlavaciellus carinatus sp. n.

( Figs 5–8 , 25 )

Type material. Holotype: MALAYSIA (Pahang): ♂, two labels: “ W. Malaysia: Pahang / Cameron Highlands / trail 9, 1400m, 27.3.93 / Löbl & Calame, #21” [white, printed], “ HLAVACIELLUS / carinatus m. / P. Jałoszyński, 2021 / HOLOTYPUS” [red, printed] ( MHNG).

Diagnosis. Body large, exceeding 2 mm in length; head in male modified, with broadly V-shaped (anteriorly concave) and sharply marked transverse carina between eyes accompanied anteriorly and posteriorly by glossy and asetose transverse impressions, and with pair of tiny tubercles behind carina; pronotum slightly narrower than elytra; each of antennomeres 3–5 as long as broad, and 6–10 each slightly elongate; aedeagus in ventral view slender, 3.5 times as long as broad and distinctly narrowing both toward apex and base; parameres with thin subapical setae.

Description. Body of male ( Fig. 5 ) stout, strongly convex, uniformly dark brown; setae slightly lighter than cuticle; BL 2.10 mm.

Head ( Fig. 6 ) broadest at large, strongly convex and coarsely faceted eyes, HL 0.45 mm, HW 0.48 mm; both frons and vertex modified, with broadly V-shaped (anteriorly concave) strongly elevated and thin transverse carina, frons in front of carina distinctly transversely impressed, vertex just behind carina also transversely impressed and with pair of tiny submedian tubercles. Punctures present only behind and in front of impressed areas, fine and inconspicuous; impressions asetose, setae in front of anterior impression sparse, long and suberect, those behind posterior impression distinctly denser and nearly recumbent. Antennae slender, AnL 1.20 mm, BL/AnL 1.75; scape indistinctly elongate, antennomeres 2–5 each as long as broad, 6–10 each slightly elongate (9 indistinctly so), 11 slightly shorter than 9–10 combined, twice as long as broad.

Pronotum subrectangular, parallel-sided between base and anterior third; PL 0.63 mm, PW 0.88 mm, PI 0.71; anterior margin weakly rounded; sides with finely crenulate lateral carinae, in posterior 2/3 straight; posterior corners right-angled and with blunt tips; posterior margin shallowly bisinuate; pronotal disc strongly convex, with area at each posterior corner distinctly impressed; antebasal pits slightly closer to posterior than to lateral margins. Punctures on pronotum fine and inconspicuous; setae long, dense, suberect.

Elytra together oval, broadest distinctly in front of middle; EL 1.03 mm, EW 0.93 mm, EI 1.11; subhumeral lines sharply marked, each developed as step-wise border between elevated humeral region and median area, as long as 0.3 EL; sides of elytra strongly rounded; elytral apices separately rounded. Punctures and setae similar to those on pronotum.

Legs long and slender, unmodified.

Aedeagus ( Figs 7–8 ) elongate and very slender; AeL 0.30 mm; median lobe in ventral view 3.5 times as long as broad, broadest near sub-basal third and with broadly rounded sides; endophallic structures distinct, with three darkly sclerotized elongate and pointed elements in basal half of median lobe; parameres with thin subapical setae.

Female. Unknown.

Distribution. Peninsular Malaysia ( Fig. 25 ).

Etymology. The adjective carinatus refers to the conspicuous transverse carina on the head of this species.

Remarks. Hlavaciellus carinatus belongs to large-bodied species, clearly exceeding 2 mm in length. The conspicuous transverse, strongly elevated and thin carina on the vertex accompanied by a pair of tiny posteromedian tubercles and two transverse impressions (anterior and posterior) is a unique apomorphy of this species.

Figures

FIGURE 25. Distribution of nominal species of Hlavaciellus.

FIGURES 5–8. Hlavaciellus carinatus sp. n., male. Dorsal habitus (5); head in anterior view (6); aedeagus in ventral (7) and lateral (8) views.