Nipponaphaenops S. Uéno, 1971

Karaoğlan, Beliz Bahar, Yekedüz, Emre, Yazgan, Satı Coşkun, Mocan, Eda Eylemer, Köksoy, Elif Berna, Yaşar, Hatime Arzu, Şenler, Filiz Çay, Utkan, Güngör, Demirkazık, Ahmet, Akbulut, Hakan & Ürün, Yüksel, 2022, Contribution to the Knowledge of the Rakantrechus Complex (Coleoptera, Carabidae, Trechini), with Description of a New Subgenus and a New Species of the Genus Nipponaphaenops S. Uéno, 1971 from Northwestern Shikoku, Western Japan, Bulletin of the National Museum of Nature and Science. Series A, Zoology (Zoology) 48 (3), pp. 119-138 : 130-131

Genus Nipponaphaenops S. Uéno, 1971

Nipponaphaenops S. Uéno, 1971: 453 (type-species: Nipponaphaenops erraticus S. Uéno, 1971: 458 ).

Diagnostic characters. Diagnosed by the combination of the following character states, all of which are present in both of the two known congeners; (1) body surface including genae glabrous apart from fixed setae; (2) head elongate (HW/HL 0.76–0.98), subparallel-sided, and proportionally (as compared with pronotum) large (PW/HW 1.14–1.30, PL/HL 1.08–1.50); (3) mentum fused with submentum; (4) mentum tooth clearly bifid at apex; (5) pronotum very elongate (PW/PL 0.79–0.86); (6) hind angles of pronotum not distinctly laterally produced; (7) baso-lateral portion of pronotum along lateral margin with a rather deep unusually elongate depression before the basal transverse impression, which is close to and subparallel with basal margin; (8) scutellum not strongly deflexed at the level of the inclined face of elytra, and elongate triangular with very acute apex; (9) inclined face of elytral basal peduncle nearly flat; (10) elytra very broad (EW/ PW 2.09–2.31) and very strongly constricted basad; (11) basal portions of elytral interval 1 including scutellar area elongate triangularly raised; (12) basal portions of elytral intervals 2–5 depressed; (13) elytral striae nearly entire, except lateral ones; (14) scutellar striole absent or vestigial; (15) apical recurrent stria relatively short and moderately arcuate, close to apical border of elytra; (16) both first and fourth pore of the marginal umbilicate series of elytra widely distant from elytral base (U1 15.8–18.8, U4 29.2–36.1); (17) internal series of elytral discal setae with two setae (located 1/7–2/11 and 3/10–4/11from base, respectively), and the external series with a single seta (located 6/11–11/17 from base); (18) preapical setae of elytra positioned before the level of the anterior end of recurrent stria (in apical 10–15% of elytra); (19) antennae and legs very long; (20) protibia with anterior face glabrous, with external face longitudinally grooved; (21) last visible ventrite with two pairs of apical setae in female.

Identification. Ishikawatrechus species usually share characters (4), (12), (13), (17), (20), (21) and sometimes (1), (14), (19) with Nipponaphaenops species; further, they are rarely close in morphometric values of (2), (5), (10), (16) to those of the latter, resulting in a body form relatively similar to the latter, and also have (3), (11), (15) too. But Ishikawatrechus species are discriminated from Nipponaphaenops species by the characters (6), (7), (8), (9), (18). Rakantrechus species usually share characters (20), (21) and sometimes (1), (3), (4), (6), (8), (9), (11), (12), (13), (14), (15), (17), (18), (19) with Nipponaphaenops species; rarely close in morphometric values of (2), (10) to those of the latter species, resulting in a body form somewhat reminiscent of the latter. However, Rakantrechus species are discriminated from Nipponaphaenops species by the characters (5), (7), (16). Kusumia species usually share characters (12), (13), and sometimes (4), (6), (7), (11), (14), (15), (18), (19) with Nipponaphaenops species; and sometimes overlapping in morphometric values of (2), (5), (10), (16) with those of the latter species, resulting in a body form fairly similar to the latter (especially to subgen. Tanakaphaenops species). But Kusumia species differ in characters (1), (3), (8), (9), (17), (20), (21) from Nipponaphaenops species.

Geographic range. West-central to northwestern area of Shikoku, southwestern Japan; between the ranges of Rakantrechus and Ishikawatrechus ( Fig. 7 ).

Remarks on distribution. Similar geographical pattern of differentiation at subgenus level is observed between Nipponaphaenops and Rakantrechus ; the ranges of two subgenera of the former basically parallel with those of the two subgenera, Rakantrechus and Izushites , of the latter ( Fig. 7 ).

Figures

Fig. 7. Map showing the distribution of the Rakantrechus Complex (in part) and anophthalmic species of the genus Trechiama in western Japan.—Light green square, Rakantrechus (s. str.); orange square, R. (Izushites); green circle, R. (Iyotrechus); yellow circle, R. (Pilosotrechiama); green triangle, Nipponaphaenops (s. str.); blue open triangle, N. (Tanakaphaenops) subgen. nov.; purple obtriangle, Ishikawatrechus; large purple circle, anophthalmic Trechiama species.—An, the type locality of Ishikawatrechus annulus Sugaya et Hara; Tk, the type locality of Nipponaphaenops (Tanakaphaenops) kojii sugen. et sp. nov. The course of the Hôyo River in the Last Glacial Maximum was drawn according to Kuwashiro (1959).