Schuelkelia unicornis, Jałoszyński, Paweł, 2015

Jałoszyński, Paweł, 2015, Schuelkelia gen. n., a new eastern Palaearctic ant-like stone beetle, with synopsis of Eurasian genera of Cyrtoscydmini (Coleoptera: Staphylinidae: Scydmaeninae), Zootaxa 4007 (3), pp. 343-369 : 352-355

Schuelkelia unicornis sp. n.

( Figs 1–16 )

Type material. Holotype: CHINA (Yunnan Province): ♂, two labels: “ CHINA: Yunnan SE Pingbian, / 22º54'31''N, 103º41'44''E, 2100m, / primary subtropical broad-leaved / forest, litter sifted, 28.VIII.2014, / leg. M. Schülke [ CH 14-22a]” [white, printed]; “ SCHUELKELIA / unicornis m. / det. P. Jałoszyński, 2015 / HOLOTYPUS ” [red, printed] (cMS). Paratypes (8 exx.): 3 ♂ (one disarticulated), 5 ♀, same data as holotype, except for yellow “ paratypus ” label (cMS, cPJ).

Diagnosis. This is the only known species of Schuelkelia and can be identified on the basis of generic diagnostic characters and structures of the aedeagus ( Figs 15–16 ).

Description. Body of male ( Figs 1–2 ) slender and moderately convex, brown, covered with setae slightly lighter than cuticle; BL 1.03–1.05 mm (mean 1.04 mm).

Head ( Figs 1–2 , 3 , 7–9 ) broadest at large, moderately convex and moderately coarsely faceted eyes, HL 0.18 mm, HW 0.18–0.19 mm (mean 0.19 mm); vertex and frons confluent, vertex laterally weakly convex, with small posteromedian horn-like projection ( Figs 7–8 ), sides of frons between eyes slightly impressed; supraantennal tubercles feebly raised. Punctures on frons and vertex inconspicuous, fine; setae short, sparse and suberect. Antennae slender but short, AnL 0.38–0.40 mm (mean 0.35 mm), antennomeres I and II strongly elongate, III–V each about as long as broad, VI slightly transverse, VII as long as broad, VIII–X each distinctly transverse, XI about as long as broad, rounded at apex.

Pronotum ( Figs 1–2 , 12 ) oval, broadest slightly in front of middle; PL 0.26–0.28 mm (mean 0.27 mm), PW 0.25–0.28 mm (mean 0.26 mm). Anterior margin nearly straight; anterior corners strongly obtuse-angled and blunt; sides strongly rounded; posterior corners indistinct, strongly obtuse-angled and broadly rounded; posterior margin arcuate with indistinct posteromedian expansion. Punctures on pronotal disc fine and inconspicuous; setae on dorsum sparse, moderately long and suberect, sides of pronotum with dense and long bristles with admixture of long, curved setae ( Fig. 13 ).

Elytra ( Figs 1–2 ) oval, broadest at middle or slightly in front of middle; EL 0.58–0.60 mm (mean 0.59 mm), EW 0.38 mm, EI 1.53–1.60; humeral calli indistinct; basal impressions absent, apices rounded together. Punctures on elytra fine and inconspicuous; setae sparse, moderately long, suberect. Hind wings absent.

Legs moderately long and slender, profemora ( Fig. 1 ) distinctly swollen, much broader than meso- and metafemora.

Aedeagus ( Figs 15–16 ) asymmetrical and stout; AeL 0.28 mm; median lobe in ventral view broadest near base, with basal orifice located in sub-median region of dorsal wall; endophallus with several darkly sclerotized and robust asymmetrical sclerites, of which two long and slender and one broad and short protrude from apical ostium; parameres short, each with single long apical seta.

Female. Similar to male but with unmodified vertex, slightly less swollen profemora, slightly smaller eyes, on average smaller body and shorter antennae; BL 0.91–0.98 mm (mean 0.95 mm); HL 0.16–0.18 mm (mean 0.17 mm), HW 0.16–0.18 mm (mean (0.17 mm), AnL 0.33–0.35 mm (mean 0.34 mm); PL 0.25 mm, PW 0.24–0.25 mm (mean 0.24 mm); EL 0.50–0.55 mm (mean 0.53 mm), EW 0.35–0.38 mm (mean 0.36 mm), EI 1.43–1.50.

Distribution and habitat. Southern part of central China; all specimens were collected by sifting leaf litter in a subtropical forest ( Fig. 17 ).

Etymology. The name unicornis refers to the tiny posteromedian horn-like projection of the vertex in male.

Figures

FIGURE 17. Collecting site of the type series of Schuelkelia unicornis sp. n. in Yunnan, China.

FIGURES 1 – 2. Schuelkelia unicornis sp. n., dorsal (1) and lateral (2) habitus of holotype male.

FIGURES 3 – 6. Morphological structures of Schuelkelia unicornis sp. n., male. Head in ventral view (3), prothorax in ventral view (4), mesoventrite in ventral view (5), and abdomen in ventral view (6). Abbreviations: ar, anterior ridge of mesoventrite; bst, basisternal part of prosternum; gp, gular plate; hr, hypostomal ridge; hy, hypomeron; hyr, hypomeral ridge; mcp, mesocoxal projection; md, mandible; mf, mesofurca; mff, mesofurcal fovea; mscc, mesocoxal cavity; mscs, mesocoxal socket; msvp, mesoventral intercoxal process; mxp 1 – 4, maxillary palpomere I – IV; nss, notosternal suture; occ, occipital constriction; pcc, procoxal cavity; pcs, procoxal socket; pff, profurcal fovea; pre, prepectus; psp, prosternal process; ptp, posterior tentorial pits; smn, submentum; tm, temple; v 3, metaventrite; vlf, ventrolateral fovea.

FIGURES 7 – 11. Morphological structures of Schuelkelia unicornis sp. n., male. Head in dorsal (7), lateral (8) and ventral (9) views, labrum in dorsal view (10) and left mandible in dorsal view (11). Abbreviations: ap, apical mandibular tooth; bst, basistipes; cd, cardo; cl, clypeus; fo, foramen occipitale; fr, frons; gal, galea; gp, gular plate; gs, gular suture; hr, hypostomal ridge; lac, lacinia; lb, labrum; md, mandible; mn, mentum; mst, mediostipes; mt, mesal mandibular teeth; mxp, maxillary palp; nr, ' neck' region; occ, occipital constriction; pmn, prementum; ppf, palpifer; pst, prostheca; smn, submentum; tm, temple; vt, vertex.

FIGURES 12 – 16. Morphological structures of Schuelkelia unicornis sp. n., male. Prothorax and elytral base in dorsal view (12), prothorax in ventral view (13), pterothorax in ventral view (14), aedeagus in ventral (15) and lateral (16) view. Abbreviations: aest 3, metanepisternum; ar, anterior ridge of mesoventrite; bst, basisternal part of prosternum; hy, hypomeron; hyr, hypomeral ridge; lmfa, lateral metafurcal arm; mcp, mesocoxal projection; mff, mesofurcal fovea; mscc, mesocoxal cavity; mscs, mesocoxal socket; msvp, mesoventral intercoxal process; mtvp, metaventral intercoxal process; nss, notosternal suture; pcc, procoxal cavity; pcr, procoxal rest (= asetose impression); pcs, procoxal socket; pff, profurcal fovea; pl, posterior lobe; pre, prepectus; psp, prosternal process; v 3, metaventrite; vlf, ventrolateral fovea.