Obesoconnus costaricanus, Jałoszyński, 2018

Jałoszyński, Paweł, 2018, First records of Archiconnus and Obesoconnus in Costa Rica (Coleoptera, Staphylinidae, Scydmaeninae), Zootaxa 4382 (2), pp. 292-298 : 293-295

Obesoconnus costaricanus sp. n.

( Figs 1–4 )

Material studied. Holotype: male ( COSTA RICA, LIMÓN PROVINCE): two labels: " COSTA RICA [CR2013-09] / Limón Province: Rd. Manganillo> / Punta Uva, 9°37'30''-38'16''N, / 82°39'41''-41'39''W, 0-10 m, degraded / coastal rain forest, car net, 1.XII.2013, / leg. M. Schülke & B. Grünberg" [white, printed], " OBESOCONNUS / costaricanus m. / Jałoszyński, 2017 / HOLOTYPUS " [red, printed) (cMS).

Diagnosis. Head between eyes with narrow longitudinal groove; EI> 1.6; median apical projection of aedeagus in lateral view S-shaped.

Description. Body of male ( Fig. 1 ) stout and strongly convex, with moderately long appendages, BL 0.95 mm; pigmentation uniformly dark brown, appendages slightly lighter, vestiture of setae light brown.

Head short, broadest at eyes, HL 0.12 mm, HW 0.27 mm; tempora absent; vertex and frons confluent and weakly convex, posterior portion of frons with a narrow longitudinal groove; supraantennal tubercles small and feebly elevated. Eyes extremely large, bean-shaped but with a very narrow posteromedian emargination, coarsely faceted and strongly convex. Punctures on vertex and frons very small, shallow and diffuse but very dense, nearly adjacent one to another, so that cuticle appears matte; setae short and sparse, recumbent to suberect. Antennae slender but short, weakly thickened distally, AnL 0.40 mm; scape and pedicel strongly elongate, antennomeres III and IV each about as long as broad, V indistinctly elongate, VI as long as broad, VII indistinctly transverse, VIII– X each distinctly transverse, XI indistinctly shorter than IX–X combined, about 1.8 × as long as broad, asymmetrical, with blunt apex.

Pronotum nearly semicircular, broadest near posterior third, PL 0.25 mm, PW 0.35 mm; all margins rounded; base with shallow and diffuse transverse groove deepened at each end and a pair of shallow and diffuse lateral impressions; pronotal disc covered with superficial but dense punctures and sparse, short, suberect setae.

Elytra oval, evenly convex, broadest slightly in front of middle, EL 0.57 mm, EW 0.35 mm, EI 1.64; humeral calli small, elongate, apices separately rounded; punctures similar to those on pronotal disc but cuticle more glossy; setae sparse, short, suberect.

Legs moderately long and slender, unmodified.

Aedeagus ( Figs 2–3 ) darkly sclerotized, AeL 0.22 mm; stout, in ventral view suboval with deeply emarginate apex with long median apical projection; the projection in lateral view strongly sinuate; parameres short and slender, each with one apical seta.

Female. Unknown.

Distribution ( Fig. 4 ). North-eastern part of Costa Rica.

Etymology. Locotypical, after the country of origin.

Remarks. All three known species of Obesoconnus are externally extremely similar ( Fig. 4 ), they also have a comparable body length (~ 0.9–1 mm), but the newly described species has different proportions of the elytra, clearly noticeable when elytral indices are compared: 1.64 in O. costaricanus vs. 1.15 in O. guyanensis and 1.22– 1.24 in O. mexicanus . All species can be easily distinguished on the basis of male genital characters. The aedeagus of O. costaricanus has the median apical projection strongly sinuate in lateral view; the projection in O. guyanensis is weakly curved dorsally, and that in O. mexicanus is apically broadened (in ventral and lateral view), nearly straight and directed not distodorsally, but distoventrally.

Figures

FIGURES 1–4. Obesoconnus costaricanus sp. n., male holotype in dorsal view (1); aedeagus in ventral (2) and lateral (3) views; distribution (4; a—O. mexicanus; b—O. costaricanus; c—O.guyanensis).