Pterostichus (Circinatus) tonkinensis Straneo 1980
Creators: name: Fedorenko, D. N.
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Carabidae
Pterostichus
Pterostichus tonkinensis

description: Pterostichus (Circinatus) tonkinensis Straneo, 1980
Figs 6, 9, 16–17, 24, 32, 35–36, 47.
MATERIAL. Paratype ♀ (MSNM; digital images), with labels: ‘ Tonkin / Montes Mauson [Mau Son]/ April,Mai 2-3000´/ H.Fruhstorfer’, red printed, combined with handwritten text ‘ Allotypus / tonkinen / sis Stran.’, ‘ Pterostichus / tonkinensis n.sp. / det. S. L. Straneo 1977/ Allotypus ’, ‘From/ Berlin / Mus.’, ‘Gift for/ 1977 / determ.’; 2♂♂ (ZMMU): Vietnam, 40 km W of Cao Bang, Phia Oac Mt., 22°36´50´´N 105°52´0´´E, h~ 1800 m, deciduous bamboo forest, 3–11.X.2018 (D. Fedorenko).
DIAGNOSIS. This new species is recognizable among all the consubgeners by a very slight constriction between pro- and mesothorax so that the pronotum and the elytra are subequally wide (vs. narrow) at their bases, the pronotum thus being subquadrate (vs. circular to oval), and the elytra being subparallel-sided. The most similar species, P. caobang Fedorenko, 2019, is distinctive in having fe 3 bisetose, tr 3 seta vestigial, and the body appearance characteristic of the subgenus.
REDESCRIPTION. With characters of the subgenus [Allegro, Sciaky, 2010; Shi, Liang, 2015; Fedorenko, 2019]. Body (Fig. 6) apterous and rather small, BL 10.5–10.6 mm, shiny black and iridescent. Extreme lateral margin of pronotum reddish, more widely so at basal angles. Antennae, palps, extreme femoral apices, and tarsi red. Dorsal microsculpture isodiametric and distinct on head, hardly traceable on pronotum and elytra, consisting of very small, moderately transverse meshes or very dense transverse lines, respectively.
Head very small, without neck constriction. Eyes convex, genae about a third as long and meeting neck at obtuse angle. Clypeus indistinctly sinuate at apical margin, frons smooth, frontal sulci short, finely and densely punctate at bottom only, parallel and very deep behind straight frontoclypeal suture, then curved toward while not reaching the level of anterior supra-ocular setae, each extended onto clypeus into a fine impressed line, with convexity outward, to adjoin clypeal seta. Labrum rectangular, subsinuate apically, with a shallow round pit at middle of apical half. Mandibular scrobe with longitudinal sulcus. Labial palpomere 3 obliquely truncate and very slightly narrower at apex than preapically. Submentum quadrisetose. Antennae just reaching pronotal base.
Pronotum quadrate, broadest two fifths from apex; sides from subequally rounded all along to nearly straight in basal half, slightly more rounded at basal angles, these slightly obtuse and blunt. Base barely oblique on sides, two fifths wider than apex, moderately punctate at bottom of and a little inside inner basolateral sulci, more sparsely so toward basal angles. Apex nearly truncate, apical angles very slightly acute, a little projecting and slightly blunted. Marginal beads fine and obliterate in middle third of base only. Lateral groove in form of a fine and well impressed line inside lateral bead, finely and densely punctate at bottom and slightly inside in apical four fifths. Inner basolateral sulci in form of deep impressed lines running parallel to each other in basal two fifths, almost reaching base; outer sulci as short and oblique lines hardly traceable between basal and lateral margins. Median line fine, deep, indistinctly crenulate. Basal and apical transverse impressions indistinct. Disc smooth, sublateral line inside lateral groove missing or vague.
Elytra very convex, oval, broadest at about middle, rounded toward humeri and in apical half, nearly straight in between; apices rounded combined; preapical sinuation rather shallow, plica distinct in lateral view. Base slightly oblique, humeri with a distinct tooth; basal ridge transverse and nearly straight, humeral angle obtuse. Striae deep, minutely punctate at bottom, stria 9 finely punctate, those 1–6 adjoining basal ridge, stria 2 adjoining parascutellar seta; parascutellar striole missing (i.e., substituted for obliterate primary base of stria 1). Intervals convex, very so toward apex, intervals 7, 5 and 3 confluent apicad in succession separate from intervals 2 and 8. This latter narrow and costate at base and at apex. Reflexed lateral margin narrow, without additional carinae. Interval 3 with single discal seta, d2, adjoining stria 2 just behind middle, stria 7 with two preapical setae. USS: 6–1–9 or 6–1–8, US 8 at about middle.
Ventral side: propleura, as well as meso- and metathorax except medially, with coarse and dense punctation, abdominal sternites II–VI more finely and rather densely punctate along sides. Prosternum without median groove; prosternal process apically truncate, not beaded, in lateral view subrectangular and blunt; inclination wide and concave, with sides edged. Metepisternum short, est3L/W 0.87. Abdominal lateral bead entire. Male sternite VII (Fig. 9) with a pair of small paramedian tubercles, a shallow transverse impression in between and two apical setae 1/3 sternite length distant from apex.
Legs: fe 3 unisetose due to distal seta missing; tarsomere 5 glabrous ventrally.
Aedeagus (Figs 16–17, 24, 32, 35–36, 47): Median lobe in lateral view strongly curved, nearly geniculate, with an oblong and shallow concavity at middle of right side; apex in dorsal view narrow and slightly curved to the left. Right paramere short triangular. Everted and inflated internal sac curved leftward and ventrad, with two large preapical bulbs, left being larger than right.
DISTRIBUTION. Known from the type locality only.
HABITATS AND HABITS. A forest-dwelling species. The type specimens were collected at ca. 600–900 m and the specimens from the Phia Oac Mt at 1.800 m elevations.
COMMENTS. This species was described based on three specimens, male holotype and two paratypes, male and female, from the Mau Son Mts in Lang Son Province, northern Vietnam. According to the description, the holotype is 11 mm in length (vs. 9.2 mm in the female paratype I measured using scale bar). This latter specimen is very slightly different from the examined specimens from the Phia Oac Mt. in having the pronotum barely wider, with base slightly wider (vs. narrower) than the elytral bases combined, and the elytral humeral tooth nearly indistinct.
description: Published as part of Fedorenko, D. N., 2023, New taxa of Pterostichus (Coleoptera: Carabidae) from Vietnam, pp. 16-39 in Russian Entomological Journal 32 (1) on pages 20-22, DOI: 10.15298/rusentj.32.1.03, http://zenodo.org/record/10949096