Pterostichus Orientostichus Sciaky & Allegro, 2013

Yin, Wenqi, Zhu, Pingzhou & Shi, Hongliang, 2023, Taxonomic study on the subgenus Orientostichus, the Pterostichus pulcher species group (Coleoptera, Carabidae, Pterostichus), ZooKeys 1175, pp. 163-185 : 163

publication ID	https://dx.doi.org/10.3897/zookeys.1175.107636
publication LSID	lsid:zoobank.org:pub:E88FF072-E8C9-45AE-A494-4B2A5F7DD7E8
persistent identifier	https://treatment.plazi.org/id/2EA92D77-CCEC-52E3-AFCB-BC6E66589349
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scientific name	Pterostichus Orientostichus Sciaky & Allegro, 2013
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Subgenus Pterostichus Orientostichus Sciaky & Allegro, 2013 View in CoL

Orientostichus Sciaky & Allegro, 2013: 113; Fedorenko 2018: 111.

Type species.

Pterostichus prattii Bates, 1890 (type locality: Wa-Shan, Sichuan, China).

Subgeneric characters.

Body moderately to strongly robust, medium to large sized, body length 13-32 mm. Terminal labial palpomere more or less expanded, usually subtriangular. Mesofemora with two setae on posterior ventral margin; metacoxae with two setae; metatrochanters without seta; fifth tarsomere usually setose ventrally. Elytral epipleura crossed. Umbilicate pore series on interval 9 continuous in middle (middle pores only slightly sparser than those near base and apex). Male sternite VII with or without secondary sexual modification. Male genitalia stout, apical lamella relatively long and twisted longitudinally. Endophallus with sclerotized projections on the ventral surface.

Taxonomic comments.

When erected, 14 species were included in the subgenus ( Sciaky and Allegro 2013). Later, Tritrichis chinensis Jedlička, 1962 was added to this subgenus as well ( Fedorenko 2018: 111). However, this species actually belongs in the genus Synuchus Gyllenhal, 1810 (see below for details).

The monophyly of the subgenus Pterostichus Orientostichus is supported by its distinctive features of the male genitalia, namely the apical lamella more or less twisted longitudinally. The relationships among the 14 previously described species are not understood, because most of these species have few taxonomic characteristics useful to recognize them except for the diverse secondary modifications on male sternite VII. Nevertheless, the relationship of P. pulcher Sciaky & Allegro with another six new species described herein is supported by their morphological similarity in several features. We define the Pterostichus pulcher species group for the species of subgenus Pterostichus Orientostichus to include those species having the elytral intervals 3 and 5 each with ≥ 3 large and foveate discal pores, interrupting intervals and forming irregularly catenulate sculpturing. Affinities of the seven species belonging to the P. pulcher species group can be supported by characteristics of the endophallus of male genitalia: endophallus asetose, basal sclerotized projection (bsp) deeply grooved in the middle, forming a spiral-shaped or U-shaped structure (Figs 19 View Figures 19–24 - 28 View Figures 25–30 ). In contrast, in Pterostichus prattii and its related species, there are coarse setae on the dorsal-apical surface of endophallus (Fig. 29 View Figures 25–30 ). Whereas in Pterostichus curtatus , P. perlutus and some undescribed species related to them, such setae are absent, and the basal sclerotized projection is not grooved but slightly hooked (Fig. 30 View Figures 25–30 ). These characteristic clearly distinguished them from the P. pulcher group species.

Morphological characters of the Pterostichus pulcher species group.

Relatively robust pterostichine beetles, medium-sized for the subgenus Pterostichus Orientostichus , BL 14.0-18.5 mm, BW 4.9-6.2 mm. Dorsal surface nearly black or a little brownish black, without evident metallic luster; mouthparts and tarsomeres sometimes reddish brown. Head medium-sized, nearly smooth. Eyes large and convex; two supraorbital setae present; frontal grooves deep, slightly sinuate, reaching mid-point of eyes; temporae short, slightly convex. Antennae exceeding pronotal base in one or two segments, antennomere 3 with or without accessory setae. Labrum and clypeus shallowly curved inward apically; mandibles straight and elongate, apex evenly curved; terminal labial and maxillary palpomere slightly expanded, subtriangular, a little more broadly expanded in males; penultimate labial palpomere with two setae along inner margin, without extra seta near apex; submentum with one lateral seta on each side. Pronotum circular or subcordate, disc with faint isodiametric microsculpture; widest near 1/3, with ≥ 1 mid-lateral setae; basal seta very close to posterior angle. Anterior margin markedly emarginate, narrowly bordered along its entire length. Anterior angles narrowly rounded, their apices not or slightly projected. Posterior margin almost straight, sometimes very shallowly concave in middle, much narrower than base of elytra between humeral angles. Disc moderately convex, often with transverse wrinkles aside median line. Basal foveae with inner and outer grooves well-defined but both without clear limits, these partly fused at base, outer groove evidently shorter than inner one. Elytra oblong, width a little greater than 1/2 of length, widest a little behind middle, with distinct isodiametric microsculpture in both males and females. Shoulders rounded, humeral angles obtuse and not projected outward, apex not dentate. Striae deep and impunctate, parascutellar pore usually absent, rarely present on base of stria 1; intervals clearly convex, elytral intervals 3 and 5 each with ≥ 3 large and foveate discal pores, sometimes discal pores also present on interval 7; these intervals are interrupted by discal pores, forming irregularly catenulate sculpturing. Umbilicate pore series on interval 9 composed of 21-23 pores, continuous in middle (middle pores only slightly sparser than those near base and apex, thus the basal, middle, and apical groups of pores cannot be clearly separated). Ventral side: Metepisternum length slightly shorter than basal width; sternite VII with one seta on each side in males, two in females; male sternite VII usually with secondary sexual modification. Fifth tarsomere setose ventrally. Male genitalia: Median lobe of aedeagus stout, curved near basal 1/3; apical lamella twisted longitudinally. Right paramere relatively short and stout, apex rounded. Endophallus strongly directed ventrally, with three sclerotized projections on ventral surface: two preapical projections very close to gonopore, small and slightly hooked; basal sclerotized projection (bsp) close to margin of apical orifice, large and deeply grooved in the middle to its left-apical side, bsp divided into two branches, left branch always narrow and simple, while right branch much thicker and showing morphology diversity among different species: dorsal surface prominent forming a hooked tubercle (Figs 19-21 View Figures 19–24 , 25 View Figures 25–30 ), apex extended and bent forming a spiral-shaped structure (Figs 22 View Figures 19–24 , 26 View Figures 25–30 ), or U-shaped with dorsal surface sinuate (Figs 23 View Figures 19–24 , 24 View Figures 19–24 , 27 View Figures 25–30 , 28 View Figures 25–30 ); gonopore lobe long and directed to the base of endophallus. Female genitalia: Gonocoxite 2 of ovipositor almost identical across in species: falciform in ventral view, length three times the basal width; outer margin with one or two minute ensiform setae, inner margin without ensiform seta; apex rounded in lateral view, with two nematiform setae in a groove (Fig. 40 View Figures 40, 41 ). Spermatheca with seminal canal and receptaculum hardly differentiated; receptaculum straight and digitate, surface smooth; seminal canal a little slenderer than receptaculum, two to three times length of receptaculum; spermathecal gland inserted on base of receptaculum (Fig. 41 View Figures 40, 41 ).

The Pterostichus pulcher species group contains the following seven species, all distributed in the Liangshan Yi Autonomous Prefecture in Sichuan province of China (Fig. 42 View Figure 42 ):

Pterostichus (Orientostichus) pulcher Sciaky & Allegro, 2013 (Meigu, E’bian);

Pterostichus (Orientostichus) pemphis sp. nov. (Puge, Zhaojue, Butuo);

Pterostichus (Orientostichus) orbicollis sp. nov. (Huili);

Pterostichus (Orientostichus) leo sp. nov. (Jinyang);

Pterostichus (Orientostichus) liyuani sp. nov. (Puge, Zhaojue);

Pterostichus (Orientostichus) condylus sp. nov. (Mianning, Xide);

Pterostichus (Orientostichus) jialini sp. nov. (Huidong).