Euconnus banana, 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 : 373-378

Euconnus banana sp. n.

( Figs 102–108 , 112 )

Type material studied. Holotype ( Japan: Okinawa Prefecture: Okinawa-jima Is. ): ♂, three labels: “Mt. Nishimedake (no. 4) / (epiphytic fern: soil) / Kunigami-son, Okinawa Is. / [Ryukyus: JAPAN] / 6.vii.2001, S. Karasawa ” [white, printed and handwritten], “Epiphytic Fern Survey / Scydmaenidae / Euconnus sp. 3 / P. Jałoszyński det., 2005” [orange, printed], “ EUCONNUS s. str. / banana m. / P. Jałoszyński, ’22 / HOLOTYPUS ” [red, printed] ( NSMT) . Paratypes (9 exx): Okinawa-jima Is.: 1 ♂, 2 ♀♀, same data as for holotype ; ♂, same data but 27.ii.2003 ; 2 ♂♂, “ Ie-rindō / Kunigami-son / Okinawa Pref. ” [white, printed], “ 16. iii. 1985 / S. Nomura leg.” ; ♂, “(RYUKYUS) / Mt. Yonahadake / Okinawa Island / 6. X. 1978 / K. Ishikawa ” [white, printed], “collected from / soil by using / Berlese funnel ” [white, printed] ; 2 ♂♂, “JAPAN, OKINAWA Island / Nago City, Nago Castle Site , / ~ 100 m, humid forest / 07.02.2019 / leg. P. JAŁOSZYŃSKI” [white, printed]. Paratypes with yellow “ PARATYPUS ” labels similar to that with holotype, deposited in NSMT, EUMJ and cPJ .

Diagnosis. Antennal club trimerous with antennomere 9 distinctly narrower than 10; males with modified mesotarsi: tarsomeres 3 and 4 each with ventral subtriangular denticle, tarsomere 5 conspicuously curved; aedeagus moderately elongate, with dorsal apical plate broadest in proximal 3/4 and with rounded sides, in distal 1/4 abruptly narrowed to form small subrectangular apical projection, ventral apical plate with broadly concave and broad distal margin, much broader than dorsal plate; endophallus with asymmetrical median sclerites.

Description. Body of male ( Fig. 102 ) elongate, strongly convex; pigmentation dark brown, appendages indistinctly lighter except for clearly lighter tarsi and maxillary palps; body covered with setae distinctly lighter than cuticle; BL 1.45–1.53 mm.

Head much narrower than pronotum, broadest at eyes, HL 0.33–0.34 mm, HW 0.26–0.30 mm; tempora in dorsal view about 2.5 times as long as eyes, behind eyes strongly and evenly convergent posterad, posterior margin of vertex strongly rounded and short, slightly bulging posterodorsad. Frons and vertex with unremarkable, fine punctures, glossy; setae sparse and suberect, tempora and posterior margin of vertex with dense thick bristles. Antennae short and compact, AnL 0.53–0.63 mm, scape and pedicel each distinctly elongate, antennomeres 3‒8 each slightly transverse, 9‒11 gradually increasing in width and length, 9 and 10 each strongly transverse, 11 slightly longer than 9 and 10 combined, about 1.3 × as broad.

Pronotum subconical but strongly narrowing posterad and with broadest site at middle or indistinctly behind middle; PL 0.40–0.45 mm, PW 0.38–0.41 mm. Base with two pairs of pits, outer pits much smaller than inner pair, but sharply marked, inner pair connected by barely noticeable faint transverse groove or not connected. Punctures and setae on disc similar to those on frons and vertex; sides of pronotum with dense thick bristles.

Elytra together oval, broadest slightly in front of middle; EL 0.73–0.78 mm, EW 0.55–0.58 mm, EI 1.30–1.41; humeral calli small, elongate, each mesally demarcated by short round impression; elytral apices separately rounded. Punctures indistinct, superficial and unremarkable; setae sparse and distinctly longer than those on pronotal disc, suberect.

Legs slender, protibiae unmodified, weakly and evenly curved, with mesal margins slightly sinuate, mesotarsi modified ( Figs 103‒104 ): tarsomeres 3 and 4 each with ventral subtriangular denticle, tarsomere 5 conspicuously curved.

Aedeagus ( Figs 105–108 ) moderately elongate and strongly sclerotized, AeL 0.38 mm; median lobe in ventral view broadest in submedian region, dorsal apical plate broadest in proximal 3/4 and with rounded sides, in distal 1/4 abruptly narrowed to form small subrectangular apical projection, ventral apical plate with broadly concave and broad distal margin, much broader than dorsal plate; endophallus with asymmetrical and strongly elongate median sclerites, two sclerites in subapical region strongly divergent laterodistad. Parameres slender, not reaching apex of median lobe, partly fused to walls of median lobe in proximal half, each with 5 apical setae of various lengths.

Female. Externally differs from male in unmodified mesotarsi. BL 1.43–1.48 mm; HL 0.33 mm, HW 0.25 mm, AnL 0.53–0.55 mm; PL 0.40–0.43 mm, PW 0.38 mm; EL 0.70–0.73 mm, EW 0.58 mm, EI 1.22–1.26.

Distribution. Japan: Okinawa Prefecture: Okinawa-jima Is. ( Fig. 112 ).

Etymology. The name banana (noun in apposition) refers to the curved, banana-like terminal mesotarsomere in males.

Remarks. Males of this species can be easily identified by the modified mesotarsi, with conspicuously curved tarsomere 5.Also the aedeagus of E. banana is remarkably different from copulatory organs in the remaining members of this group. Females can be matched to males if collected together on the same spot; the known distribution of this species does not overlap with any similar species. However, the aedeagus must always be examined, because yet undescribed similar species may occur on Okinawa-jima and surrounding islands.

Figures

FIGURE 112. Distribution of Euconnus taiwanus Franz, and E. banana sp. n.

FIGURES 102‒108. Euconnus banana sp. n., male. Dorsal habitus (102); mesotarsus (103‒104); aedeagus in ventral (105, 107) and lateral (106, 108) views.