Pterostichus (Petrophilus) eximius rishiridakensis, Sasakawa & Berlov & Okuzaki, 2020

Sasakawa, Kôji, Berlov, Oleg & Okuzaki, Yutaka, 2020, Taxonomic and nomenclatural changes in three species of Pterostichus Bonelli (Coleoptera: Carabidae) from the Far East, Zootaxa 4822 (3), pp. 416-424 : 419-420

Pterostichus (Petrophilus) eximius rishiridakensis ssp. nov.

Figs. 1 , 2

Pterostichus sachalinensis: Yasuda et al. (1991) : 23; Morita (1995): 3.

Pterostichus (Petrophilus) eximius: Yoshimatsu et al. (2018) : 96.

Type materials. Holotype: ♂, Mt. Rishiri-dake, alt. 1690 m near the summit, Rishiri-tô Island, Hokkaidô, Japan , 21–28.vi.2019, Y. Okuzaki leg. in KS coll . Paratypes: 3♀, same data as the holotype in KS coll .; 1♂ 7♀, “Mt.Rishiri III Oshidomari Rishiri Is., Hokkaidô JAPAN 1. VII.1990 M.Sato, E. Nishiyama N. Yasuda leg. ” in RTM [according to Yasuda et al. (1991), the locality and collection date are as follows: Mt. Rishiri-dake , alt. 1300 m, 1400 m, or 1500 m, 26.vi.–1.vii.1990.]

Diagnosis. Distinguished from P. e. eximius and P. e. sachalinensis by straight dorsal contour of lateral sides at subapical part of the aedeagus. Distinguished from sympatric consubgeneric species P. thunbergi ( Yasuda et al. 1991; Sasakawa & Okuzaki 2020) by rounded hind angle of pronotum (obtuse to right-angled in P. thunbergi ) and the presence of setae on ventrolateral sides of last hind tarsal segment (absent in P. thunbergi ).

Description. External characters: Body length: ♂, 10.99–12.02 mm (n = 2); ♀, 10.75–12.55 mm (mean ± SD: 11.69 ± 0.52 mm, n = 10). Dorsal surface of the body black and shiny, without metallic luster; females less shiny than males ( Figs. 2A, B ). Legs except for femur reddish to dark brown. Hind wings reduced to minute vestiges. Head normal-sized; eyes convex; tempora not swollen; frontal impressions distinct, with the posterior end in front of the anterior supraorbital setae; antennal segment 2 with one seta. Pronotum subcordate, convex except for laterobasal impressions and the area around the basal 1/4–1/3 of the median line, which are depressed; anterior and hind angles rounded; lateral margins arcuate throughout; median line distinct, reaching posterior margin in all specimens and anterior margin in some specimens; two marginal setae on each lateral side, anterior setae on apical 1/3 and posterior setae on hind angles; surface smooth except for laterobasal impressions, which are only slightly punctuate. Elytra oblong; shoulders distinct but not denticulate; scutellar stria present, connected to stria 1 in some specimens; one setigerous puncture at the anterior end of stria 1; four to six setigerous punctures on interval 3, with the most anterior one adjoining stria 3 in all specimens; apices rounded, not denticulate. Male sternum 7 without sexual characteristics. Ventrolateral sides of the last hind tarsal segment with one to three setae.

Male genitalia: Aedeagus without a tubercle, bent at about 90 degrees at the basal third; dorsal contour of each lateral side at subapical part straight ( Figs. 2C, E ); apex narrowly rounded from dorsal view ( Fig. 2D ). Endophallus ( Figs. 2C, E ) stout, short, and bent ventrally at the base; left dorsolateral surface near the ostium weakly sclerotized; left ventral lobe large, with two relatively similar-sized sub-lobes (lv-1 and lv-2); right ventral lobe large, with two different-sized sub-lobes (rv-1 and rv-2); left lateral lobe small (ll); dorsal lobe absent; relative sizes of lobe and sub-lobes as follows: rv-1 ≫ lv-1> lv-2> rv-2 ≈ ll; gonopore weakly sclerotized, without a gonoporal piece. Left paramere wide, square. Right paramere ( Fig. 2F ) slender, bent at about 140 degrees at basal 2/5; apical 1/3 shallowly arcuate ventrally; apex narrowly rounded.

Female genitalia: Stylomere 2 ( Figs. 2G, H ) with two short setae on outer margin, one shorter seta on inner margin; apical nematiform seta more than twice as long as marginal setae.

Figures

FIGURE 1. Differences in male genital structures (top, left posterolateral view; bottom, right ventrolateral view) among subspecies of Pterostichus eximius. Red, green, and blue arrows denote sublobe rv-2 on the endophallus, a swelling adjoining lobe ll on the endophallus, and the dorsal contour at the aedeagal subapex, respectively. Phylogenetic relationships inferred from these characters are shown.

FIGURE 2. Habitus (A, B), male genitalia (C–F), and female genitalia (G, H) of Pterostichus eximius rishiridakensis ssp. nov. A, dorsal view of holotype male; B, dorsal view of paratype female; C, right lateral view of aedeagus with everted endophallus (holotype male); D, dorsal view of aedeagal apex (paratype male); E, left lateral view of aedeagus with everted endophallus (holotype male); F, left lateral view of right paramere (holotype male); G, dorsal view of right stylomere 2 (paratype female); H, ventral view of right stylomere 2 (paratype female). gp, gonopore; ll, left lateral lobe; lv-1, basal sub-lobe of left ventral lobe; lv-2, apical sub-lobe of left ventral lobe; rv-1, basal sub-lobe of right ventral lobe; rv-2, apical sub-lobe of right ventral lobe.