Circinatus 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 : 3-5

Taxon classification Animalia Coleoptera Carabidae

Subgenus Circinatus Sciaky, 1996

Subgeneric characters.

The subgenus Circinatus is defined as follows: body length between 9.3-16.5 mm; elytral length approx 0.6 times body length or more; dorsal side blackish, without metallic color, elytron sometimes with iridescent shine. Eye large and convex; two supraorbital setae present; third antennomere glabrous except apical setae; terminal palpomere tubiform in both sexes; penultimate labial palpomere without seta near apex; submentum with two setae on each side, outer one much shorter than inner one. Pronotum usually round; hind angle usually completely rounded, rarely weakly defined; posterior seta distant from hind angle or located near hind angle; basal foveal inner groove long, poorly defined; outer groove less than half length of inner one, or completely absent; region between inner and outer grooves sometimes concave, so that basal fovea is present as a simple depression. Elytron with basal setigerous pore present; scutellar stria present, complete or nearly so; third interval with two setigerous pores (rarely one or three as individual aberrations), all adjacent to second stria, anterior one at approx middle, the posterior one at approx posterior fourth; ninth interval with umbilical pore series discontinuous and sparse in middle; seventh interval with two umbilical pores near apex. Metepisternum short, its length subequal to width of anterior margin; males with secondary sexual structures on terminal or penultimate sternum, or without such structures on sterna. Mesofemur with two setae on posterior margin, with single short spine subapically; metacoxa with two setae; metatrochanter with one seta; first metatarsomere with distinct carina on outer surface, more or less shallower in second and third metatarsomeres; fifth tarsomeres usually glabrous beneath, rarely setose. Male genitalia with apical orifice placed on dorsal side of aedeagus or somewhat twisted to left side; right paramere straight, slightly elongate, ratio length / width 2.5-4, apex rounded or obtuse. Endophallus variable, located on dorsal or ventral side of aedeagus. Female genitalia with spermatheca markedly elongate, seminal canal and receptaculum differentiated; receptaculum capitate or clavate; spermathecal gland inserted near base of receptaculum. Stylomere II saber-shaped, elongate, strongly bent outwards; outer margin with two (rarely three) ensiform setae, inner margin with one (rarely two) ensiform seta; two short nematiform setae located in a furrow near apex (Fig. 138). Female sternum VIII with transparent region in middle, V-shaped, triangular or quadrate, apical margin with fine setae or spines; female tergum VIII with apical half evenly chitinized.

Comparison.

The majority of the species in the subgenus Circinatus (16 of 22 known species) have a rounded pronotal hind angle and the pronotal posterior seta is distant from the hind angle. In the Chinese fauna of Pterostichus , six subgenera have this type of pronotum: Eosteropus Tschitschérine, Oreolyperus Tschitschérine, Circinatus Sciaky, Gutta Wrase & Schmidt, Tubuliphallus Sciaky & Allegro, and Sinosteropus Sciaky. Two of these subgenera have distributions that are distant from the others: Eosteropus is widely distributed in the Palearctic realm, and Oreolyperus is restricted to middle Asia. The distributions of the other four subgenera are close in range in southern China.

In comparison with Eosteropus and Gutta , Circinatus differs in having the elytral third interval usually with two setigerous pores, all pores adjacent to the second stria (the third interval usually with three pores, the first one adjacent to the third stria in the other two subgenera). Compared to Oreolyperus , Circinatus differs in having the elytral basal pore present (elytral basal pore absent in Oreolyperus ). Compared to Tubuliphallus , Circinatus differs in having the elytral length more than 0.6 times the body length, apical orifice of aedeagus opened to the dorsal or left side (in Tubuliphallus , elytral length approximately 0.5 times the body length, apical orifice of aedeagus opened to the apex). Compared to Sinosteropus , Circinatus differs in: body size large (9.5-16.5 mm); body form less convex and relatively slender; pronotal basal fovea with the outer area of the inner groove usually flat or concave; right paramere straight and only slightly elongate. In Sinosteropus , the body size is small (6-10 mm); body form strongly convex and relatively stout; pronotal basal fovea with the outer area of the inner groove convex; right paramere usually strongly elongate, apex more or less bent.

Some species of the subgenera Morphohaptoderus Tschitschérine and Neohaptoderus Tschitschérine may have similar rounded pronotal hind angles. However, in these two subgenera, the posterior seta of the pronotum is always located very close to the hind angle, which distinguishes these subgenera from most species of Circinatus . Some species of Morphohaptoderus have pronota shaped similarly to Circinatus , but have a different number of setae on the metacoxa and male genitalia (for details see discussion under Pterostichus schuelkei ).

Some species of Circinatus have a weakly defined hind angle and a pronotal posterior seta close to the hind angle (e.g., Pterostichus baenningeri ), and these species therefore might have been misplaced into the subgenus Neohaptoderus . However, these species of Circinatus differ from the species of Neohaptoderus in having the pronotal basal foveal inner groove shallower and relatively weakly defined, the outer groove obsolete, and the apical orifice of the aedeagus opening ventrally. In Neohaptoderus , the pronotal basal foveal inner groove is deeper and always well defined, the outer groove is typically distinct, and the apical orifice of the aedeagus does not open ventrally.

Distribution.

This subgenus includes 22 species and one subspecies, all endemic in China. The highest diversity is present in central-south Sichuan province (13 species), while other species are distributed in Yunnan (4 species), Guizhou (2 species), Chongqing (1 species), Guangxi (1 species) and Hubei (1 species) provinces (Maps 1, 2). All species are relatively narrowly distributed. Many of them were known only from one locality.

Literature.

In the present concept, the first species of Circinatus was described by Fairmaire (1888), although the original name licinoides is unavailable due to homonymy. Later, Jedlička described two more species ( Jedlička 1931, 1934). However, in his time, these three species were not assigned to subgenera and were listed only as "incertae sedis" in his monograph ( Jedlička 1962). Sciaky (1996) first established the subgenus Circinatus , and he added three new species. Later, one new species was described from Shaanxi ( Sciaky and Wrase 1997). Allegro and Sciaky (2010) reviewed the subgenus Circinatus , described six new species and provided a key to all known species. Prior to the present work, a total of 13 species was included in the subgenus Circinatus , but two of these species actually do not belong in this subgenus.

Key to species of subgenus Circinatus