Stenichnodes (s. str.) cordicollis, Jałoszyński, 2020

Jałoszyński, Paweł, 2020, Three new species and new records of Stenichnodes Franz (Coleoptera Staphylinidae: Scydmaeninae), Zootaxa 4779 (2), pp. 289-296 : 290

Stenichnodes (s. str.) cordicollis sp. n.

( Figs 1 , 7–10 )

Type material. Holotype: IVORY COAST: ♂, two labels: “IVORY COAST Tai / Forêt de Tai 17.X.80 / tamisage ss. bambous / Mahnert - Perret» [white, printed], « STENICHNODES (s. str.) / cordicollis m. / P. Jałoszyński, 2020 / HOLOTYPUS ” [red, printed] ( MHNG).

Diagnosis. Elytral apex in male unmodified; protarsomere I in male with short anteroventral projection and slightly curved; antennae conspicuously slender, antennomeres IX and X each about as long as broad; aedeagus with asymmetrical parameres, of which one is bifurcate.

Description. Body of male ( Fig. 1 ) elongate and slender, strongly convex, moderately dark brown, covered with yellowish vestiture; BL 1.01 mm.

Head broadest at large, strongly convex and finely faceted eyes, HL 0.16 mm, HW 0.20 mm; tempora slightly shorter than half length of eye in lateral view; vertex weakly convex and anteriorly confluent with frons; frons flattened, between indistinct supraantennal tubercles with a pair of tiny and diffuse round impressions. Each eye beanshaped, transverse in relation to the long body axis, with narrow posteromedian emargination. Vertex and frons with fine, inconspicuous punctures; setae fine, nearly recumbent, barely discernible under magnification 100 ×. Antennae conspicuously slender, with slightly flattened, trimerous club, AnL 0.43 mm; antennomeres I–II strongly elongate, III slightly transverse, IV–VIII each indistinctly elongate, IX–X each about as long as broad, XI about 1.2 × as long as broad, much shorter than IX and X combined, with rounded apex.

Pronotum heart-shaped, broadest near anterior third; PL 0.28 mm, PW 0.25 mm. Anterior and posterior margins weakly rounded, sides in anterior half strongly rounded; posteriorly distinctly constricted; base with shallow but distinct transverse groove deepened at middle to form diffuse pit. Punctures on pronotal disc inconspicuous, fine and sparse; setae sparse, short and recumbent, with a few erect setae on sides near each hind corner.

Elytra together oval, broadest distinctly behind middle; EL 0.58 mm, EW 0.43 mm, EI 1.35; humeral calli indistinct, basal impressions absent; apices rounded together. Punctures on elytra slightly more distinct than those on pronotum, but superficial and inconspicuous; setae sparse, short, suberect.

Hind wings absent.

Legs long and slender; protarsi modified, with tarsomere I slightly curved (dorsally convex) and with short anteroventral projection.

Aedeagus ( Figs 7–10 ) elongate and with thick walls, in ventral view median lobe asymmetrical, especially in apical region, with long and flat apical projection; parameres present, massive and asymmetrical, one bifurcate, with asymmetrical branches, one bearing two setae, the other one asetose; AeL 0.28.

Female. Unknown.

Distribution. Southwestern Ivory Coast.

Etymology. The adjective cordicollis refers to the heart-shaped pronotum.

Remarks. Stenichnodes cordicollis is highly unusual in having the aedeagus with strongly modified, asym- metrical parameres, of which one is bifurcate, with one branch broadening distad and bearing apical setae, and the other tapering and lacking setae. Bifurcate parameres were not known in Scydmaeninae , and they are rarely found among Staphylinidae (examples can be found among Euaesthetinae , e.g., Puthz (2008)).

Figures

FIGURES 1–6. Dorsal habitus (1−2, 4, 6) and elytral apices in male (3, 5). Stenichnodes cordicollis sp. n. (1); S. spinosus sp. n. (2−3); S. bouakensis sp. n. (4−5); S. ceylonensis (Franz), specimen from India (6).

FIGURES 7–14. Aedeagus in ventral (7, 9, 11, 13) and lateral (8, 10, 12, 14) views. Stenichnodes cordicollis sp. n. (7−10); S. spinosus sp. n. (11−14).