Euconnus (s. str.) kirin, Jałoszyński, 2022

Jałoszyński, Paweł, 2022, Taxonomy of ' Euconnus complex'. Part XXIV. Intermediate forms between Psomophus, Eupentarius and Euconnus s. str. in the East Palaearctic fauna unify problematic subgenera (Coleoptera, Staphylinidae, Scydmaeninae), Zootaxa 5194 (3), pp. 343-391 : 352-354

Euconnus (s. str.) kirin sp. n.

( Figs 29–36 , 110 )

Type material studied. Holotype ( Japan: Kanagawa Prefecture): ♂, three labels: “JAPAN, Kanagawa Pref. / Sagamiko / 25 V 2002 / leg. P. JAŁOSZYŃSKI” [white, printed], “rotten wood / under dead dec. tree” [white, printed], “ EUCONNUS s. str. / kirin m. / P. Jałoszyński, ’22 / HOLOTYPUS ” [red, printed] ( NSMT) . Paratype: ♀, “JAPAN, Kanagawa Pref. / Sagamiko / 14 VII 2002 / leg. P. JAŁOSZYŃSKI” [white, printed]. Paratype with yellow “ PARATYPUS ” label similar to that with holotype, deposited in cPJ .

Diagnosis. Antennal club clearly trimerous and stout; head distinctly elongate, with vertex bulging posterodorsad and in males with pair of large and clearly delimited lateral frontal impressions connected at middle by deep transverse groove; pronotum subconical, with one pair of tiny antebasal pits connected by extremely faint, barely noticeable transverse groove, and with indistinct sublateral carinae; protibiae in males unmodified, weakly and evenly curved; aedeagus weakly sclerotized, in ventral view drop-shaped, with symmetrical pair of strongly elongate endophallic sclerites in subapical region resembling horns with several short and pointed branches.

Description. Body of male ( Fig. 29 ) elongate, strongly convex; pigmentation moderately dark brown, legs, antennae and palps indistinctly lighter, antennal clubs not darkened; body covered with setae distinctly lighter than cuticle; BL 1.23 mm.

Head ( Figs 35‒36 ) nearly as large as pronotum, broadest at eyes, distinctly elongate, HL 0.30 mm, HW 0.25 mm; tempora in dorsal view over twice as long as eyes, behind eyes strongly and evenly convergent posterad, posterior margin of vertex strongly rounded, strongly bulging posterodorsad. Frons with deep transverse groove broadened at each side, median region directly behind groove slightly impressed, and region in front of groove distinctly bulging (best visible in lateral view; Fig. 35 ); each side of anterior head region with large, oval impression. Frons and vertex with unremarkable, fine punctures, glossy; setae sparse and suberect, frontal groove surrounded by denser and shorter nearly recumbent setae, tempora with dense but short thick bristles. Antennae short and compact, with compact and broad trimerous club, AnL 0.43 mm, scape and pedicel each elongate, antennomeres 3‒10 each transverse (3‒8 weakly, 9 and 10 strongly so), 11 slightly shorter than 9 and 10 combined, about as long as broad.

Pronotum subconical, broadest slightly behind middle; PL 0.30 mm, PW 0.28 mm. Base with one pair of tiny antebasal pits connected by extremely faint, barely noticeable transverse groove, and with indistinct sublateral carinae. Punctures and setae on disc similar to those on frons and vertex; sides of pronotum with sparse thick bristles.

Elytra together oval, broadest slightly in front of middle; EL 0.63 mm, EW 0.43 mm, EI 1.47; humeral calli poorly marked and mesally not demarcated by elongate impressions; elytral apices separately rounded. Punctures distinct but very shallow, superficial and diffuse, unremarkable; setae sparse and only slightly longer than those on pronotal disc, only slightly suberect.

Legs slender, protibiae unmodified, weakly and evenly curved.

Aedeagus ( Figs 30–34 ) stout, drop-shaped, weakly sclerotized, AeL 0.23 mm; median lobe in ventral view broadest in subapical region, sides rounded, in lateral view median lobe weakly curved, dorsal apical plate in ventral view subtriangular but with narrowly truncate apex; endophallus in subapical region with conspicuous pair of elongate and barbed, horn-like sclerites ( Fig. 33 ). Parameres broad and short, not reaching apex of median lobe, each with 4–5 apical and subapical setae of various lengths, parameral base with a thick collar.

Female. Externally similar to male (including conspicuously large head), but lacking modifications on frons. BL 1.25 mm; HL 0.30 mm, HW 0.25 mm, AnL 0.40 mm; PL 0.30 mm, PW 0.30 mm; EL 0.65 mm, EW 0.48 mm, EI 1.37.

Distribution. Japan: Honshū (Kantō region) ( Fig. 110 ).

Etymology. The epithet kirin (noun in apposition) refers to a pair of endophallic sclerites ( Fig. 33 ) that resemble horns on the head of the kirin, a mythical creature well-known in Japan.

Remarks. The only nominal species similar to E. kirin is E. yaimanus (see next description), whose male also has a strongly modified head. The latter species, however, occurs on the south-westernmost Yaeyama Islands, has clearly different modifications of the frons ( Figs 35‒36 vs. 46‒47), and different aedeagal structures ( Figs 30‒34 vs. 38‒45).

The holotype and paratype of this species were collected by sifting leaf litter and rotten wood on the western slope of Mt. Arashiyama near the lake Sagamiko (municipality Sagamihara), at the altitude ~ 350 m, in a deciduous forest with oaks.

Figures

FIGURE 110. Distribution of Euconnus rectitibia sp. n., E. kirin sp. n., E. yaimanus sp. n., and E. uchinaanchu sp. n.

FIGURES 29‒34. Euconnus kirin sp. n., male. Dorsal habitus (29); aedeagus in ventral (30, 32) and lateral (31, 34) views; endophallic sclerites in ventral view (33).

FIGURES 35‒36. Euconnus kirin sp. n., male. Head in anterodorsal (35) and lateral (36) views.