Taxonomic study on the subgenus Orientostichus, the Pterostichus pulcher species group (Coleoptera, Carabidae, Pterostichus) Author Yin, Wenqi https://orcid.org/0000-0003-2903-1399 College of Forestry, Beijing Forestry University, Beijing 100083, China Author Zhu, Pingzhou https://orcid.org/0000-0003-2139-6764 Department of Entomology, College of Plant Protection, China Agricultural University, Beijing 100093, China Author Shi, Hongliang https://orcid.org/0000-0002-9989-5830 College of Forestry, Beijing Forestry University, Beijing 100083, China shihl@bjfu.edu.cn text ZooKeys 2023 2023-08-16 1175 163 185 http://dx.doi.org/10.3897/zookeys.1175.107636 journal article http://dx.doi.org/10.3897/zookeys.1175.107636 1313-2970-1175-163 E88FF072E8C945AEA4944B2A5F7DD7E8 CE03B1B394CF56B48E8F7E5026CD639C Pterostichus (Orientostichus) orbicollis sp. nov. Figs 2 , 8 , 14 , 20 , 25 , 35 Chinese vernacular name: 圜胸通缘步甲 Type locality. China, Sichuan province: Liangshan Yi Autonomous Prefecture, Huili county, Longzhoushan mountain ( 26.79N , 102.20 E, alt 3500 m). Type material. Holotype : ♂: "China: Sichuan, Huili county, Longzhoushan mt., way to the peak, Rhododendron shrubs + meadow, by pitfall trap", "3500 m, N26.7921, E102.2035, 2015.VII.19, Shi HL, Liu B & Ma YL lgt., BJFU exp. 2015", "HOLOTYPE ♂ Pterostichus (Orientostichus) orbicollis sp. nov. det. Yin & Shi, 2022" [red label]; Paratypes : 6 ♂ and 16 ♀: the same data as holotype but labeled as paratypes. Diagnosis. Elytral intervals 3 and 5 each with ≥ 3 large foveate discal pores, interval 7 without discal pore. Antennomere 3 with accessory setae. Pronotum nearly circular; posterior angles completely rounded without denticle (Fig. 8 ); lateral margins with one mid-lateral seta. Male sternite VII with a well-defined smooth tubercle (Fig. 35 ). Apical lamella of aedeagus short and wide (LL/LW = 1.1-1.25), apex rounded (Fig. 14 ); endophallus with right branch of bsp tuberculate on dorsal surface (Figs 20 , 25 ). Figures 25-30. 25-28 endophallus bsp of Pterostichus pulcher species group, left lateral view 25 P. orbicollis sp. nov., paratype from Longzhoushan mountain, Huili county 26 P. liyuani sp. nov., paratype from Luojishan mountain, Puge county 27 P. condylus sp. nov., paratype from Mianning county 28 P. pulcher Sciaky & Allegro, paratype from Yizi Yakou, E'bian county to Meigu county 29, 30 Endophallus of Pterostichus (Orientostichus) spp., left lateral view and right lateral view 29 P. prattii Bates, 1890, a male from Sanming city, Fujian province 30 P. curtatus Fairmaire, a male from Heqing county, Yunnan province. Scale bars: 1 mm. Abbreviations: gp: gonopore, gpl: gonopore lobe, bsp: basal sclerotized projection, vb: ventral basal lobe. Figures 31-33. Holotype of Pterostichus pulcher Sciaky & Allegro, 2013 31 habitus and labels 32 pronotum 33 male genitalia, left lateral view and dorsal view of median lobe of aedeagus. Scale bars: 5 mm ( 31 ); 1 mm ( 32, 33 ). Comparison. From the presence of accessory setae on antennomere 3 and relatively short apical lamella of male genitalia, P. orbicollis sp. nov. is most similar to P. pemphis sp. nov. But these two species can be easily distinguished by the differences on the number of pronotal mid-lateral setae and shape of pronotal posterior angles (details see Comparison under the latter species). Description. BL = 14.7-15.8 mm, BW = 5.5-6.0 mm, dorsal surface and appendages black, elytra sometimes a little reddish brown. Antennomere 3 with accessory setae on apical 2/3 in additional to the primary setae forming apical ring. Pronotum nearly circular, PW/PL = 1.30-1.34, widest near anterior 1/3; anterior margin wider than posterior margin; strongly narrowed to base (PBW/PW = 0.66-0.69); lateral margins evenly arched from anterior angles to posterior angles; posterior angles completely rounded, without a trace of denticle (Fig. 8 ); lateral margins with only one mid-lateral seta near maximum width; basal foveae impunctate, inner and outer grooves straight, partly fused at base, outer groove a little shorter than inner one, area between them slightly depressed; disc with fine transverse wrinkles aside median line. Elytra oblong, parascutellar pore absent; intervals 3 and 5 each with ≥ 3 large foveate discal pores; interval 7 without discal pore. Male sternite VII with well-defined tubercle on middle, small and smooth (Fig. 35 ). Median lobe of aedeagus stout, strongly curved near basal 1/3; apical lamella gradually narrowed and deflected ventrally; apical lamella slightly twisted longitudinally, relatively short (LL/LW = 1.1-1.25), with rounded apex (Fig. 14 ). Endophallus long, straightly directed ventrally, gonopore opened to ventral-basal direction of aedeagus; vb distinct, spherical, rounded at both apexes; bsp deeply grooved, nearly U-shaped, dorsal surface of right branch folded and strongly hooked forming a tubercle (Figs 20 , 25 ). Distribution. This species was only found in the type locality, Longzhoushan mountain, Huili county, Liangshan Yi Autonomous Prefecture (Fig. 42 ). Etymology. The scientific name of the new species is composed of two Latin roots, orbi - meaning circular, and - collis meaning pronotum, referring to its completely rounded pronotum.