Pterostichus expolitus Fedorenko, 2019

Fedorenko, D. N., 2019, New species of Pterostichus subgenus Circinatus (Coleoptera: Carabidae: Pterostichini) from Vietnam, Russian Entomological Journal 28 (4), pp. 358-369 : 366

3. Pterostichus expolitus Fedorenko , sp.n.

Fig. 3 .

MATERIAL. Holotype ♀ ( ZMMU), labelled: ‘N-Vietnam, 40 km W of Cao Bang, Phia Oac Mt. , E [astern]-slope, h~ 1600–1800 m, 22°36´27´´N / 105°52´0´´E, deciduous forest, 22.V–6.VI.2018, leg. A. Abramov’.

DIAGNOSIS. A slender large-sized species distinctive in having character combination as follows: single discal elytral seta; pronotum cordate and quadrisetose, with posterolateral seta inserted in basal angle, sides subsinuate before rounded basal angles, apical bead widely obliterate at middle, lateral bead extended slightly inside base; inner, deep and impunctate, basal sulcus only present; elytral base with humeral tooth vestigial and no lateral bead; parascutellar striole long; meso- and metatarsomeres 1–3 carinate and sulcate laterally; both metatrochanteral seta and distal femoral seta missing.

DESCRIPTION. Body ( Fig. 3 ), BL 15.4 mm. Pronotum and elytra slightly iridescent, with microsculpture hardly traceable, consisting of dense transverse lines.

Head: Frontal sulci parallel, shallow and short, shortened from behind. Labrum subsinuate apically.

Pronotum quadrisetose, cordate, broadest about 2/5 from apex; sides rounded medially, straight behind apical angles, subsinuate in front of very obtuse and rounded basal angles; PW/PL 1.06, PW/HW 1.49. Base truncate, oblique laterally, barely narrower than apex, PB/PA 0.87. Apex evenly subsinuate between slightly projecting, acute and rather sharp, angles; apical bead obliterate in middle third. Disc convex and smooth, basal and apical transverse impressions missing, median line fine, obliterate basally and apically, fine lateral bead extended slightly inside basal angle. Inner basal sulci deep and smooth, running parallel on basal 2/5, not quite reaching base, outer basal sulcus as a very short vestige close to basal angle. Posterolateral seta in basal angle.

Elytra oblong subovate (EW/EL 1.67, EW/PW 1.23), broadest behind middle, with very narrow base, no humeri, and indistinct preapical sinuation; apices rounded and subtruncate combined; sides rounded, diverging and straight from basal 1/5 to 1/2. Base long, with obliterate lateral bead and vestigial humeral tooth; basal ridge nearly straight, humeral angle obtuse and sharp. Striae deep, minutely and sparsely punctate at bottom, lateral groove in basal half with fine and denser punctures. Intervals almost flat, barely more convex at base. Parascutellar striole entire. Discal seta d2 about 3/5 distant from base. USS: 18+19.

Underside smooth, except mesepisternum rather sparsely punctate within peduncle and abdominal sternite II more densely punctate. Prosternum with a fine yet distinct medial groove; prosternal process obtuse and blunt in lateral view; declivity convex, flat just below mesothoracic peduncle, moderately wide and costate in middle part. Metepisternum as wide as long.

Legs: Meso- and metatarsomeres 1–3 carinate and sulcate laterally. Metatrochanteral seta and distal metafemoral seta missing.

NAME. Refers to very shiny body dorsum.

DISTRIBUTION. Known from the type locality only, Mt. Phia Oac , northern Vietnam .

HABITATS AND HABITS. The only female was taken by pitfall-trapping.

Figures

Figs 1–3. Dorsal habitus: 1 — Pterostichus phiaoc sp.n., female paratype; 2 — P. caobang sp.n., holotype; 3 — P. expolitus sp.n., holotype. Рис. 1–3. Габитус дорЗально: 1 — Pterostichus phiaoc sp.n., паратип самка; 2 — P. caobang sp.n., голотип; 3 — P. expolitus sp.n., голотип.