Nebria (Falcinebria) dichotoma, Sasakawa, 2020

Sasakawa, Koji, 2020, Taxonomic studies of the ground beetle subgenus Falcinebria Ledoux & Roux, 2005 (Coleoptera, Carabidae, Nebria) from Honshu, Japan, ZooKeys 902, pp. 37-60 : 37

Nebria (Falcinebria) dichotoma sp. nov. Figs 14 , 31 , 32 Japanese name: Dando-hime-marukubi-gomimushi

Nebria reflexa : Uéno (1985): 56 (part); Nakane (1963b): 19 (part).

Notes.

This species is known only from the type locality, Mount Takanosu. Among known related species, it is similar to N. chugokuensis sp. nov. in having a relatively large-sized body and larger PPW/EL but is distinguished by a lack of concavity on the ventral surface of the aedeagal apex.

Description.

Body length: ♂, 9.80-10.34 mm (mean ± SD: 10.14 ± 0.22 mm, n = 5); ♀, 10.49-11.12 mm (mean ± SD: 10.79 ± 0.30 mm, n = 6). PPW/EL: ♂, 0.314-0.335 (mean ± SD: 0.322 ± 0.010, n = 5); ♀, 0.302-0.324 (mean ± SD: 0.312 ± 0.008, n = 6). Ventral surface of aedeagal apex not concave. Dorsobasal lobe absent. Dorsomedian lobe small, directed right-laterally. Dorsoapical lobe with two small protrusions at the basal part; the apical portion directed ventrally, bifurcated in a Y-shape. Right laterobasal lobe large, with the width from a ventral view wider than the width of the gonopore protrusion from a lateral view. Left laterobasal lobe large, with the width from a ventral view wider than the width of the gonopore protrusion from a lateral view. Right lateroapical lobe bifurcated at the base in a V shape, with one apex directed posterolaterally and the other directed anterolaterally; the posterolateral apex very small; the anterolateral apex smaller than right laterobasal lobe. Left lateroapical lobe bifurcated at the middle in a Y shape, with one apex directed posterolaterally and the other directed anterolaterally; the posterolateral apex smaller than the anterolateral apex; the anterolateral apex smaller than the right laterobasal lobe. Ventrobasal surface with a pair of swelling adjoining each laterobasal lobe; swellings conjoined; ventrobasal swelling absent.

Type materials.

Holotype: ♂ (NARO), Mount Takanosu (= Mount Dando), alt. 1000 m, Shitara-machi, Aichi Prefecture, Japan, 8.vi.1971, K. Tanaka & H. Ohira leg. Paratypes (NARO): 2♂4♀, same data as the holotype; 2♂2♀, same locality and collector (1♂2♀, 24.vi.1972; 1♂, 4.viii.1972).

Etymology.

The specific name derives from the Greek word dichotoma (divided into two) and refers to the apical portion of the dorsoapical lobe.

Figures

Figures 5 - 16. Habitus dorsal view of Nebria spp. 5 N. reflexa, a male from the type locality 6 N. sagittata sp. nov., holotype male 7 N. iidesana sp. nov., holotype male 8 - 10 N. niohozana males from Mount Chokai (8), Doai, a locality close to the type locality designated for the lectotype (9), and Mount Hakusan (10); 11 N. furcata sp. nov., holotype male 12 N. pisciformis sp. nov., holotype male 13 N. kuragadakensis sp. nov., holotype male 14 N. dichotoma sp. nov., holotype male 15 N. uenoi, a male from the type locality 16 N. chugokuensis sp. nov., holotype male.

Figures 31 - 35. Right lateral (a), ventral (b), dorsal (c), and posterodorsal (d) views of the endophallus and left laterodorsal view of the dorsoapical lobe (e) of Nebria spp. 31 N. dichotoma sp. nov., holotype male 32 N. dichotoma sp. nov., paratype male from the type locality 33 N. uenoi, male from the type locality 34 N. chugokuensis sp. nov., holotype male 35 N. chugokuensis, paratype male from Sandan-kyo. ac, concavity of aedeagal apex; remaining abbreviations are provided in Figures 17 - 21.