Pterostichus (Nialoe) namahage Sasakawa & Mitsuduka, 2023

Sasakawa, Koji & Mitsuduka, Yoshiji, 2023, A morphology-based revision and phylogenetic analysis of the Pterostichus macrogenys species group (Coleoptera, Carabidae) and implications for differentiation of the species group, Deutsche Entomologische Zeitschrift 70 (2), pp. 291-310 : 291

Pterostichus (Nialoe) namahage Sasakawa & Mitsuduka sp. nov.

Figs 2A , 4A-D , 6A

Type material.

Holotype, ♂, Haraikawa, Honzanmonzen, Funagawaminato, Oga-shi, Akita Prefecture, Japan (MGRS: 54SUK92241 16384; 39.89067718°N, 139.73961047°E), 28. v-30. vi. 2022, subterranean baited trap, Y. Mitsuduka leg., in the collection of NSMT (Fig. 2A ).

Description.

Body length (mm). ♂ (n = 1), BLm 13.15, BLl 12.32, BLc 11.96.

Head. Mandibular surface with several short wrinkles at middle. Anterior-posterior length of tempora slightly longer than anterior-posterior length of eye. Surface of clypeus smooth. Antennal segment 2 with two setae. Mentum tooth shallowly bifid; width between paired apices three times anterior-posterior length between level of mentum apices to level of innermost part of median notch.

Pronotum. Lateral margin arcuate on apical 4/5, only slightly sinuate on basal 1/5. Anterior margin emarginated, with contour arched more strongly than curvature of apical 4/5 of lateral margin. Posterior margin slightly emarginated at median area and slightly arcuate at lateral areas, with curvatures of both the same as curvature of basal 1/5 of lateral margin. Hind angles slightly acute. Median line absent near anterior margin and in front of transverse grooved area between laterobasal impressions. Transverse grooved area between laterobasal impressions concave to same degree as laterobasal impressions. Surface including laterobasal impressions smooth.

Elytra. Scutellar-stria not connected to stria 1. One setigerous puncture in front of level of posterior end of scutellum. Posterior setigerous punctures on interval 3 slightly in front of posterior 1/4.

Abdominal ventral sides. Sternum 7 of male moderately concave, with degree of concavity greater than that of convexity of median area of sterna; shape of concave area transverse ellipse; posterior margin of ellipse corresponding to posterior margin of sternum; anterior-posterior length of concave area slightly longer than 1/2 anterior-posterior length of sternum 7; transverse, major axis of ellipse about 1.4 times that of longitudinal minor axis; area corresponding to minor axis of ellipse posterior to major axis slightly raised.

Male genitalia. Endophallus with gonopore directed basal-ventrally; left pigmented band weakly sclerotised; distinct right preapical lobe absent, but corresponding area slightly swollen; left preapical lobe with basal part protruding left-laterally; left apical lobe short, not bent, bifurcated (Fig. 4A-D ). Relative sizes of lobes: right apex of bifurcated left apical lobe apex ≈ basal protrusion of left preapical lobe >> left apex of bifurcated left apical lobe apex. Right paramere short, straight, with apex rounded (Fig. 6A ).

Female. Unknown.

Etymology.

The specific name is a noun in apposition and derives from Namahage, which is a famous folk event held on the Oga Peninsula, where the type specimen was collected.

Figures

Figure 2. Habitus dorsal view of the Pterostichus macrogenys species group. A. Pterostichus namahage sp. nov. holotype male from Haraikawa; B. P. kamurosanus sp. nov. holotype male from Ariya; C. P. atsumidakensis sp. nov. holotype male from Take-no-koshi; D. P. asahinus male from Momoyake.

Figure 4. Endophallus of Pterostichus namahage sp. nov. holotype male from Haraikawa (A-D), P. kamurosanus sp. nov. holotype male from Ariya (E-H), P. atsumidakensis sp. nov. holotype male from Take-no-koshi (I-L) and P. asahinus male from Momoyake (M-P). Fully inflated endophallus in left lateral (A, E, I, M), apical (B, F, J, N), right lateral (C, G, K, O) and basal part in dorsal and apical part in ventral (D, H, L, P) views. Abbreviations: go - gonopore; lal - left apical lobe; lpb - left pigmented band; lpl - left pre-apical lobe; rpl - right pre-apical lobe.

Figure 6. Right paramere of Pterostichus namahage sp. nov. holotype male from Haraikawa (A), P. kamurosanus sp. nov. holotype male from Ariya (B), P. atsumidakensis sp. nov. holotype male from Take-no-koshi (C-E), P. asahinus male from Momoyake (F-H), P. chokaisanus male from Momoyake (I), P. chokaisanus male from Zao-chuo-kogen (J), P. kitakamisanus male from Odateminami (K, L) and P. kitakamisanus holotype male from Genbeidaira (M). Left lateral (A-C, F, I-K), right lateral (L, M), apical part in apical and basal part in ventral (D, G) and apical part in dorsal (E, H) views.