Tohlezkus uminchu Jałoszyński, 2023

Jałoszyński, Paweł & Wakimura, Ryotaro, 2023, A new genus, new species and new records of Eucinetidae in Japan and Taiwan (Coleoptera), Zootaxa 5351 (1), pp. 122-138 : 133-136

Tohlezkus uminchu Jałoszyński sp. n.

( Figs 23–33 , 35–36 , 38 )

Type material studied. Holotype ( JAPAN): ♁, two labels: “JAPAN, OKINAWA Pref. / OKINAWA-jima, 26 ii 2023 / Ohkuni-rindo, Jashiki / 26°45'15.7''N / 128°14'44.8''E / leg. P. JAŁOSZYŃSKI”, “ TOHLEZKUS / uminchu m. / Jałoszyński ‘23/ HOLOTYPUS” ( NSMT) . Paratype: 1 ♀, same data as for holotype (cPJ) .

Diagnosis. Apical rod-like region of maxillary palpomere 4 shorter than 1/4 length of entire palpomere; posterior marginal carina of anterior metaventral process forming inversely U-shaped anterior expansion at middle; triangular median region of metaventrite about as long as 1/3 length of metacoxal plate; lateral margin of metacoxal plate barely noticeably rounded and in anterior half straight; each paramere with distinctly concave mesal margin in distal 1/3.

Description. Body of male ( Figs 2 , 23–24 ) elongate oval, strongly convex dorsally and flattened ventrally, brown with umbra hue, appendages indistinctly lighter than body, setae slightly lighter than cuticle; BL 1.18 mm.

Head ( Figs 25–28 ) broadest at eyes, HL 0.13 mm, HW 0.26 mm; lateral margins of head behind eyes in dorsal view straight, vertex and frons together weakly convex, strongly transverse; punctures on dorsum small, sharply marked and evenly distributed, separated by spaces 2–3 × as wide as diameters of punctures, microsculpture of frons and vertex scale-like; setae short and sparse, weakly suberect, directed anteriorly. Genae ( Fig. 27 ) and short postgenae asetose; gula and submentum asetose.

Antennae ( Fig. 29 ) distinctly longer than length of entire head capsule, AnL 0.25 mm; scape narrower than pedicel, transverse, pedicel subquadrate, antennomeres 3–10 each distinctly transverse, 11 subquadrate, nearly as long as 9–10 combined.

Pronotum ( Figs 2 , 23 , 25 ) less convex than elytra, broadest at posterior corners, PL 0.23 mm, PW 0.43 mm. In dorsal view, anterior and lateral margins strongly and evenly rounded; posterior corners strongly projecting posteriorly and sharp-angled; posterior margin bisinuate, medially strongly and evenly convex. Punctures and setae on pronotal disc similar to those on frons and vertex, but surface not microsculptured. Hypomera asetose and virtually impunctate.

Elytra ( Figs 2 , 23 ) together oval, broadest near anterior fourth and strongly narrowing posteriorly to broadly subtriangular apex; EL 0.83 mm, EW 0.58 mm, EI 1.42. Punctures and setae similar to those on frons and vertex, surface with weak scale-like microsculpture.

Hind wings vestigial.

Legs ( Figs 24 , 30–32 ) short, robust, flattened dorsoventrally. Profemora with row of dense, thick setae along anterior margin in basal half of ventral surface; remaining legs unmodified. Apical spurs on mesotibiae ( Fig. 32 ) equal in length, sinuate, with rounded apices.

Aedeagus ( Figs 35 , 38 ) strongly elongate, AeL 0.25 mm; penis tapering towards subtriangular apex with membranous, inflatable preputial sac, lateral margins of penis straight; in sole studied male penis with exserted slender flagellum; parameres massive, at base as broad as penis, tapering towards rounded apices, with mesal margins clearly concave in distal third.

Female. Externally indistinguishable from male. BL 1.23 mm; HL 0.13 mm, HW 0.28 mm, AnL 0.28 mm; PL 0.23 mm, PW 0.48 mm; EL 0.85 mm, EW 0.60 mm, EI 1.42. Gonocoxites ( Fig. 36 ) subtriangular elongate, setose on outer margins, each with minute subconical and pointed gonostylus bearing several long setae.

Distribution. Southwestern Japan: Okinawa Island.

Etymology. The noun in apposition uminchu is taken from the Uchinaaguchi language of Okinawa-jima; its meaning is “a person of the sea”, or, in a narrower sense, a fisherman, referring to the islandic origin of the new species.

Remarks. Specimens used in this study were collected by sifting leaf litter and rotten wood in subtropical forest.

Adults of Tohlezkus uminchu are the smallest among species known to occur in Japan and Taiwan ( Fig. 2 vs. 3–4). They resemble T. orientalis in the umbra body pigmentation (distinctly reddish in T. rufus ). Tohlezkus orientalis , known to occur in Taiwan, apart from having a proportionally much larger aedeagus with parameres longer in relation to the penis and with less concave mesal margins, has a much longer apical rod-like portion of the maxillary palpomere 4 (illustrated in Vít (1981): figs 1, 2). The Japanese T. rufus is most similar to T. uminchu in the relative length and structure of the aedeagus, but clearly differs in several ventral characters compared in Fig. 33 ( T. uminchu ) and Fig. 34 ( T. rufus ) and listed in the key.

Figures

FIGURES 23‒24. Tohlezkus uminchu sp. n. Dorsal (23) and ventral (24) habitus.

FIGURES 25‒29. Tohlezkus uminchu sp. n. Head and pronotum in anterodorsal view (25); head in dorsal (26) and ventral (27) views with suctorial mouthparts tilted ventrally; labrum and prelabium directed ventrally (28); left antenna in ventral view (29).

FIGURES 30‒32. Tohlezkus uminchu sp. n. Head and thorax in ventral view (30); middle leg in ventral view (31); apical spurs of mesotibia in ventral view (32).

FIGURES 33‒34. Metaventral features to distinguish Tohlezkus uminchu sp. n. (33) from T. rufus (M. Sakai) (34). Arrowheads indicate (from left to right): anterior marginal line of anterior metaventral process; shape of median region of metaventrite exposed between metacoxal plates; and shape of lateral margin of metacoxal plate.

FIGURES 35‒36. Tohlezkus uminchu sp. n. Aedeagus (35) and ovipositor (36) in ventral view.

FIGURES 37‒40. Aedeagus. Bisayodes hure gen. & sp. n. (37); Tohlezkus uminchu sp. n. (38); Tohlezkus orientalis Vít (39); Tohlezkus rufus (M. Sakai) (40).

FIGURES 1‒4. Dorsal habitus of males. Bisayodes hure gen. & sp. n. (1); Tohlezkus uminchu sp. n. (2); Tohlezkus orientalis Vít (3); Tohlezkus rufus (M. Sakai) (4).