Trephionus cylindriphallus Sasakawa

Sasakawa, Koji & Ito, Hirotaro, 2018, Taxonomic notes on the ground beetles in the genus Trephionus Bates, 1883 from central Honshu, Japan (Coleoptera, Carabidae, Sphodrini, Synuchina), ZooKeys 742, pp. 91-104 : 94

Trephionus cylindriphallus Sasakawa sp. n. [Japanese name: Chichibu-hoso-hirata-gomimushi] Figs 3, 12, 13

Type material.

Holotype: ♂, Kawamata, University Forest in Chichibu, The University of Tokyo, Ôtaki, Chichibu-shi, Saitama Pref., 16.X.2009, N. Nishiyama leg. Paratypes: 1♂2♀, same data as the holotype; 1♂3♀, same locality as the holotype (1♂, 17.X.2008, K. Ômura leg.; 1♀, 1.IX.2005, Ômura leg.; 1♀, 6.X.2005, Ômura leg.; 1♀, 10.IX.2009, K. Nishiyama leg.); 1♂, Ôjiro near Abe Pass, Minobu-cho, Yamanashi Pref., 1-2.X.2003, K. Sasakawa leg.; 1♂, Shimakura-rindô, asl. ca. 1000 m, Ôshika-mura, Nagano Pref., 14.IX.1998, M. Hama leg.

Diagnosis.

Similar to T. kinoshitai and T. niumontanus sp. n. in having secondary setae on dorsal side of mid and hind tarsal segment 5, but distinguished from the former by barely sinuate lateral margin of pronotum near base and from the latter by smaller body.

Description.

Body length: ♂, 8.9-9.8 mm (mean ± SD: 9.4 ± 0.36 mm, n = 5); ♀, 8.2-10.0 mm (mean ± SD: 9.3 ± 0.84 mm, n = 5). PI: ♂, 1.23-1.25 (mean: 1.24, n = 5); ♀, 1.19-1.24 (mean: 1.22, n = 5). Dorsal surface blackish brown to black. Pronotal lateral margins before hind angles barely sinuate (Fig. 3). Mid and hind tarsal segment 1 bisulcate, segment 5 with two secondary setae on dorsal side. Apex of aedeagus rounded; endophallus (Figs 12, 13) stout, almost straight, directed posteriorly; gonopore opening directed right-dorsolaterally; dorsobasal lobe barely swollen; right laterobasal lobe widely swollen, with BD as wide as AW; left laterobasal lobe absent; dorsoapical lobe semi-ellipsoid, with BD less than half of AW; sclerotization of sclerotized lobe weaker than of aedeagus; anteroposterior length of sclerotized rim of gonopore as long as proximodistal length of sclerotized lobe.

Etymology.

The name refers to the robust, cylindrical shape of the endophallus.