Pterostichus (Tschitscherinea) spectabilis sp. nov.

Figures 4, 18, 37–38, 44

Chinese vernacular name: îdzā±Ƥ

Type locality. China, Yunnan province: Lijiang, Ninglang County, Luguhu, Gouzuandong (N27.63°, E100.82°, alt 3367 m) .

Type material. Holotype, male (IZAS): “ CHINA, Yunnan, Lijiang, Ninglang, Luguhu, Gouzuandong, N27.63205, E100.81781 ”, “ 3367m, 2009.VII.19, Shi H.L. coll., Pitfall trap, Inst. of Zoology, CAS.”, “HOLOTYPE of Pterostichus (Tschitscherinea) spectabilis sp. nov. det. Yin & Shi, 2024” [red label] . Paratypes (a total of 1 male and 1 female), 1 female (IZAS): the same data as holotype but date 2009.VII.17, and labeled as paratype; 1 male (IZAS): “ CHINA, Sichuan, Yanyuan County, Mianbu Town, Shangluoshuidong, mixed forest, 3468m, N27.5721, E101.2120 ”, “ 2018.VII.23, pitfall trap. Shi H.L., Yan W.F., Zhu P.Z. & Jiang Z.Y. lgt., IZAS & BJFU exp. of 2018”, “ PARATYPE of Pterostichus (Tschitscherinea) spectabilis sp. nov. det. Yin & Shi, 2024” [red label] .

Diagnosis. Very large and macrocephalic species, much larger than other species of the subgenus, BL = 14.8– 15.5 mm (versus 9.0– 12.5 mm in other species); maxim width of head at outer margin of tempora; pronotum subquadrate; basal foveae distinctly ridged between lateral margin and outer groove. Elytra with isodiametric microsculpture (Fig. 44); parascutellar pore absent; interval 3 with two setigerous pores; metatarsomere thickened in both sexes (Figs 37–38), with outer-lateral ridge on metatarsomere 1; right paramere falcate, not carinate on dorsal surface, apex rounded (Fig. 18).

This remarkable new species can be readily distinguished from all other related species by the very large size and macrocephalic body form.

Description. BL = 14.8–15.5 mm, BW = 4.6–4.8 mm, dorsal surface and appendages dark reddish brown. Head very large and strongly thickened, slightly narrower than maxim width of pronotum, HW/PW = 0.78–0.81; frons without puncture; antennae short, hardly reaching elytra base; eyes very small, tempora strongly swollen behind eyes, length greater than eyes, eyL/tpL = 0.56–0.65, maxim width of head at outer margin of tempora. Pronotum subquadrate, PW/PL = 1.13–1.17, PBW/PW = 0.71–0.74, widest near anterior fourth; anterior margin slightly wider than posterior margin, PAW/PBW = 1.04–1.07; anterior angles narrowly rounded, apex weakly projected; lateral margins subparallel, nearly straight before posterior angles; posterior angles rectangular, apex with a faint denticle. Basal foveae shallow, with a few punctures; inner and outer grooves faintly defined, area between them depressed; outer groove about two-thirds length of inner one; area between lateral margin and outer groove distinctly ridged. Pronotum disc with fine transverse wrinkles aside median line; median line shallow. Elytra oblong and parallel-sided, BW/EL = 0.62–0.65, with isodiametric microsculpture in both sexes (Fig. 44); parascutellar stria joined to stria 1, angular base of stria 1 relatively long, stria 1 entire; parascutellar pore absent; humerus with small tooth, slightly projected out; elytral interval 3 with two setigerous pores, both adjacent to stria 2, the first one near middle, the second one near apical fifth. Male sternite VII without secondary sexual modification; metafemora slightly thickened in males; metatarsus in a stout form in both sexes, more thickened in males (mt1 length/width = 1.7 in males, = 2.1 in females, Figs 37–38); metatarsomere 1 with outer-lateral ridge. Median lobe of aedeagus small (length about 1.70 mm), apex not bent ventrally in lateral view; apical lamella short and wide, apex rounded, not twisted to right; right paramere falcate, elongated and curved, apical portion thickened, not carinate on dorsal surface, cross-section ovate at middle, apex rounded (Fig. 18). Endophallus not studied due to restricted male materials.

Distribution. This species is known from two localities on the border of Sichuan and Yunnan provinces (China): Luguhu, Ninglang county and Mianbu pass, Yanyuan county. (Fig. 54, blue)

Etymology. The scientific name of the new species is derived from Latin, which means spectacular, referring the new species is remarkable among all Pterostichus species in southwest China for its special macrocephalic body form and relatively large size.