Pterostichus (Circinatus) maitreya, Shi, Hongliang & Liang, Hongbin, 2015

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 : 15

Taxon classification Animalia Coleoptera Carabidae

Pterostichus (Circinatus) maitreya sp. n. Figures 13, 41, 63, 79, 99, 120

Type locality.

Guizhou: Fanjingshan Mt. (N27.90°, E108.70°), altitude 1778-1973 m.

Type material.

Holotype (IZAS): male, body length = 13.5 mm, pin mounted, genitalia dissected and glued on plastic film pinned under specimen, "CHINA, Guizhou, Jiangkou, / Fanjing Mt. S. Slope, 4500-/ 5300 steps, 1778-1973 m / N27.90180, E108.70372 -/ N27.90784, E108.70052 "; "2012.VIII.25 night, on tree / trunk, broadleaf forest, SHI / Hongliang, HUANG Xinlei, / LIU Yizhou leg. IOZ, CAS / 梵净山4500–5300步”; "HOLOTYPE ♂/ Pterostichus (Circinatus) / maitreya new species / des. SHI H.L. 2015" [red label]. Paratypes, a total of 4 males and 1 female: 1 male (IZAS): "CHINA, Guizhou, Fanjing Shan, 2300 m, 2001.7.31, Liang H.B. leg.". 2 males, 1 female (IZAS): " CHINA, Guizhou, Fanjing Shan, 2000 m, 2001.8.1, Liang H.B. leg.". 1 male (IZAS): "CHINA, Guizhou, Jiangkou, Fanjing Mt. south slope, 4500 steps (Huixiangping), N27.90180, E108.70372, 1778 m, 2012.VIII.25 day, on ground, broadleaf forest, HUANG Xinlei leg. ".

Diagnosis.

Pronotum with single mid-lateral seta; posterior seta located almost at hind angle; hind angle forming an indistinct obtuse angle; elytron with linear microsculpture; males with two small tubercles on terminal sternum; fifth tarsomeres glabrous beneath.

There are five Circinatus species ( Pterostichus maitreya , Pterostichus baenningeri , Pterostichus yan , Pterostichus ailaoicus and Pterostichus miao ) similar in the following external and genital characters: (1) male terminal sternum with two tubercles; (2) pronotal posterior seta very close to hind angle; (3) aedeagus with median lobe slender, apical lamella located on the right side of apex, narrower than half width of apical orifice apex; (4) elytral microsculpture linear, sometimes hardly visible. These five species are considered to be closely allied with each other. The differences among them are listed in Table 1.

These five species have relatively similar median lobe of aedeagus, but significant differences are expected to be found in the endophallus. We studied only Pterostichus baenningeri and Pterostichus maitreya sp. n. Most endophallic lobes of these two species can be recognized as homologous, but their shapes and positions are all different (Figs 40, 41).

Description.

Body form slightly elongate, relatively large species within subgenus, body length 13.0-13.8 mm; dorsal side almost black, moderately shining, elytron with iridescent shine; mouthparts, antenna, tarsus, tibia, and apex of femur reddish brown; ventral side blackish. Both sexes with elytral microsculpture weak and linear. Head. Frons without punctures; antenna reaching elytron basal fifth; gena shorter than length of eye, briefly tumid behind eye. Pronotum nearly round, lateral margin strongly curved, widest a little before middle; posterior margin a little narrower than anterior margin; PW/PL = 1.13-1.17; one mid-lateral seta present, located a little before greatest width; posterior seta very close to hind angle; hind angle forming an indistinct obtuse angle; basal fovea shallow, faintly defined; inner groove subparallel to median line, basal half oblique outwards; outer groove very faint, indistinct but present, close to hind angle, approx one fourth length of inner one, outer area of inner groove flat; basal foveal area with fine punctures on inner side of inner groove. Elytron oviform, with basal ridge slightly curved; elytral shoulder moderately widened, shoulder angle between basal ridge and lateral margin forming obtuse angle, humeral tooth very small, not pointed; intervals feebly convex; striae moderately deep, without punctures; scutellar stria short, apex free; third interval with two setigerous pores adjacent to second stria; umbilical pore series on ninth interval sparse in middle, composed of 16-17 pores (6, 1-2, 9-10). Ventral side. Proepisternum and mesepisternum impunctate, metepisternum finely punctate; male terminal sternum with two small tubercles, located a little before middle of sternum, region between tubercles slightly depressed. (Fig. 120). Legs. Fifth tarsomeres glabrous beneath; males with apical half of mesotibia widened, inner margin crenulate; first two metatarsomeres with distinct carina on outer surface, such carina on basal half of third metatarsomere superficial. Male genitalia. Median lobe of male genitalia bent approx 90 degrees, apex abruptly bent ventrally (Fig. 41A); ventral margin straight in middle, strongly bent ventrally near apex; dorsal margin gradually curved; apical orifice large, slightly turned to left side, opened on ventral side; in lateral view, apical lamella short, laminate with base slightly thickened, not twisted, its length approx one eighth length of apical orifice; in dorsal view, apical lamella short and rounded, located on right side of median lobe apex, pointing apical-ventrally, its base distinctly grooved on dorsal surface; length of apical lamella approx equal to its basal width (Fig. 41B). Right paramere straight and stout, subtriangular, apical half slightly enlarged, apex strongly narrowed and slightly hooked, length approx three times greatest width, apex pointed (Fig. 41C). Endophallus (Fig. 41D, E, F) bent to ventral side across left side of aedeagus, major parts of endophallus located on ventral side of aedeagus (in lateral view); gonopore (gp, gonopore lobe folded in Fig. 41) located at level a little before apical lamella, pointing to aedeagal base. Six distinct lobes recognized: basal lobe (bl) small and compressed, close to base of apical lamella, lower surface strongly chitinized; dorsal lobe (dl) small and rounded, close to apex of apical lamella, membranous without decoration; ventral lobe (vl) large, completely rounded, located on ventral side of endophallus, decorated with very fine scales; pre-apical lobe (pa) close to lf, evenly rounded; right lobe (rl) small and helicon-shaped, located on base of vl, decorated with fine scales; left lobe (lf) largest, on left side of endophallus, just before gp, elongated and slightly bent, decorated with large spines, gradually changing to fine scales from lobe apex to gp. Endophallus without any chitinized piece. Female genitalia. Spermatheca with seminal canal approx five times as long as receptaculum; receptaculum capitate (Fig. 63), club approx half length of receptaculum; seminal canal inserted at base of common oviduct, base of seminal canal not sclerotized. Stylomere II with two ensiform setae at basal half of outer margin, and one near middle of inner margin; two short nematiform setae located in a furrow near apex. Female sternum VIII (Fig. 79B) with sparse fine setae on posterior margin; posterior margin almost straight, slightly notched in middle; posterior region chitinized; anterior region semi-chitinized, without denser pigmented spots, deeply notched in middle; middle transparent region triangular, adjacent to anterior and posterior notches in middle. Female tergum VIII (Fig. 79A) with major portion semi-chitinized, without denser pigmentation; lateral-anterior region with two chitinized patches; anterior margin slightly notched in middle, posterior margin arcuate.

Distribution.

This species is known only from Fanjingshan Mt. in Guizhou Province (Map 1). The altitude range is 1778-2300 m.

Etymology.

This new species is named for Maitreya Buddha. Its type locality Fanjingshan Mountain (= Mount Fanjing) is one of the sacred Buddhist mountains of China, and is traditionally regarded as the bodhimanda of bodhisattva Maitreyabuddha (Mi Le Fo in Chinese).

Affinities.

Pterostichus maitreya sp. n. is close to Pterostichus baenningeri , Pterostichus yan sp. n., Pterostichus ailaoicus sp. n. and Pterostichus miao sp. n. in their similarities of male terminal sternum and male genitalia (see diagnosis above).

Habitat.

Specimens of Pterostichus maitreya sp. n. were collected from mid-high altitude mixed forest at Fanjingshan Mountain. They were found running along living tree trunks during the night. It is presumed that this species hides under bark in the day, and hunts on living tree trunks at night.