Pterostichus (Circinatus) subtilissimus Sciaky, 1996

Shi, Hongliang & Liang, Hongbin, 2015, The genus Pterostichus in China II: the subgenus Circinatus Sciaky, a species revision and phylogeny (Carabidae, Pterostichini), ZooKeys 536, pp. 1-92 : 39-41

Taxon classification Animalia Coleoptera Carabidae

Pterostichus (Circinatus) subtilissimus Sciaky, 1996 Figures 21, 45, 67, 84, 106

Pterostichus (Circinatus) subtilissimus Sciaky 1996: 227 (Original: Pterostichus ( Circinatus ); holotype deposited in CRS); Bousquet 2003: 488; Lorenz 2005: 280; Allegro and Sciaky 2010: 4.

Type locality.

Sichuan: Emei Shan Mt. (= Emei Mountain), 2800 m.

Type material examined.

Holotype of Pterostichus subtilissimus Sciaky (CRS): male, body length = 14.8 mm, board mounted, genitalia dissected and mounted on plastic film, pinned under specimen, "Cina- W Sichuan / Emei Shan 2800 m. / 25-31.VI.92. Sauer"; "HOLOTYPUS ♂ / Pterostichus / (Circinatus)/ subtilissimus sp. n. / Det. Sciaky, 1994" [red label].

Non-type material examined

(total 4 specimens). 1 male (IZAS), "China, Sichuan Prov., Mount Emei, Leidongping; 2420 m, N29.54669, E103.33552, 2012.VII.02, in dead log, SHI Hongliang & LIU Ye lgt."; 1 female (IZAS), "China, Sichuan Prov., Mount Emei, Leidongping; 2420 m, N29.54669, E103.33552, 2012.VII.02 night, on tree trunk, SHI Hongliang & LIU Ye lgt."; 1 male, 1 female (IZAS), "China, Sichuan Prov., Mount Emei, Leidongping; 2420 m, N29.54669, E103.33552, 2012.VII.06, by pit fall trap, SHI Hongliang & LIU Ye lgt.".

Diagnosis.

Pronotum with single mid-lateral seta; posterior seta distant from hind angle, hind angle completely rounded; basal foveal grooves incompletely fused, anterior part of outer groove distinctly separated from inner one, so that basal fovea is a little bifid anteriorly; elytron with faint transverse microsculpture; basal ridge almost horizontal; shoulder angle forming obtuse angle, humeral tooth distinct, short and obtuse; males with terminal sternum not modified; median lobe of aedeagus strongly bent to right side, strongly constricted at middle of apical orifice, apical lamella very short, less than one fourth its basal width.

Pterostichus subtilissimus is very similar to Pterostichus dentifer and Pterostichus yuxiaodongi sp. n. They are all relatively large-sized species within the subgenus, and have the aedeagus strongly bent to the right side. Pterostichus subtilissimus differs from the latter two species by: (1) elytral basal ridge almost horizontal, humeral tooth pointing laterally (basal ridge strongly oblique, humeral tooth pointing lateral-posteriorly in the latter two species); (2) body form slenderer, elytron narrower than the latter two species; (3) median lobe of aedeagus strongly constricted in the middle part of apical orifice (not constricted in the latter two species).

Supplemental description.

Male sternum. Penultimate and terminal sterna of males without special structures. Endophallus (Fig. 45D, E, G) completely membranous, without any chitinized piece or heavy scale; bent to dorsal side of aedeagus, all parts of endophallus located on dorsal side of aedeagus; in dorsal view, endophallus rolled counter-clockwise a full circle, gonopore (gp, gonopore lobe folded in Fig. 45) located close to left margin of apical orifice, pointing to aedeagal apex, region around gp finely pigmented with spots; two major lobes recognized: basal lobe (bl) large and rounded, located at level of apical lamella; middle lobe (ml) narrower and longer than bl, apex finely stained, located on right margin of apical orifice, just supporting constriction on right face of aedeagus (Fig. 45D). Female genitalia. Spermatheca with seminal canal approx 4.5 times as long as receptaculum; receptaculum capitate (Fig. 67), club approx half length of receptaculum; seminal canal inserted at base of common oviduct, base of seminal canal sclerotized. Stylomere II with two ensiform setae at outer margin, and one near middle of inner margin; two very short nematiform seta located in a furrow near apex. Female sternum VIII (Fig. 84B) with fine and sparse spines on posterior margin; posterior margin slightly curved, strongly notched in mid dle; posterior region chitinized; anterior region semi-chitinized, deeply and widely notched in middle; middle transparent region V-shaped, adjacent to anterior and posterior notches, oblique extensions of V-shaped transparent region with sparse spots. Female tergum VIII (Fig. 84A) well chitinized, a narrow area close to posterior margin lighter, with irregular small spots; anterior margin deeply notched in middle.

Distribution.

So far this species is known only from the type locality, Emei mountain in Sichuan province. The altitude range is between 2420-2800 m. (Map 2)

Affinities.

This species is close to Pterostichus dentifer and Pterostichus yuxiaodongi sp. n. For details see discussions under Pterostichus yuxiaodongi sp. n. and subtilissimus -group.