Pterostichus (Steropanus) fossifrons Fedorenko, 2020

Fedorenko, D. N., 2020, New taxa of Pterostichini (Coleoptera: Carabidae) from Vietnam, Russian Entomological Journal 29 (1), pp. 38-52 : 45-46

Pterostichus (Steropanus) fossifrons Fedorenko , sp.n.

Figs 16–18 , 23, 26 .

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, 22.V–6.VI.2018, leg. A.Abramov’.

DIAGNOSIS. This species is similar to P. aequus ( Andrewes, 1937) in appearance. According to the description, P. aequus has pronotal sides indistinctly sinuate, frontal sulci less deep, pronotal basal angles obtuse and more rounded, and impressed line (= outer basal sulcus extended into a remnant of basal bead) less deep than in P. glymmiger . In the new species, pronotal sides are distinctly sinuate just in front of basal angles, frontal sulci very deep, much deeper than those of P. glymmiger , pronotal angles in form of a blunt obtuse tooth, and the impressed line just as in P. glymmiger .

DESCRIPTION. BL 13.9 mm. Body ( Fig. 16 ) shiny black. Antennae, palps, femoral apices, tibiae and tarsi rather dark reddish brown. Dorsal microsculpture fine-meshed: isodiametric and almost imperceptible on head; superficial yet distinct over pronotum and elytra, consisting of barely transverse or narrow transverse meshes, respectively. Head rather densely micropunctate, pronotal punctation much sparser and much finer in part; elytral micropunctation indistinct.

Head: Eyes as in previous species. Frontal sulci indistinctly crenulate at bottom, very deep S-shaped, running parallel to each other just behind clypeus, strongly diverging on frons, slightly incurved and then abruptly disappearing just in front of the level of anterior supra-ocular seta; finest posterior extensions of frontal sulci diverging toward, running just inside, and disappearing just behind the level of postero-ocular setae. Supra-ocular groove deep, slightly incurved anteriorly. Labrum subsinuate apically, sexsetose, with inner four setae slightly separate from lateral ones. Antennae not quite reaching pronotal base.

Penultimate labial palpomere as in P. securipenis sp.n. Terminal labial palpomere two thirds as wide at apex as long at inner margin, somewhat pentagonal because of very convex outer margin.

Pronotum cordate, PW / PL 1.18, PW /HW 1.65, broadest two fifths from apex, PLw/ PL 0.42; sides evenly rounded, sinuate just in front of basal angles. Base slightly sinuate medially, oblique towards basal angles, as wide as apex, PB/ PA 1.02; basal angles as fairly small, obtuse and blunt tooth. Apex gently sinuate, with a slight convexity towards subrectangular and blunt apical angles. Apical bead vestigial, extremely fine and hardly traceable, obliterate in middle third; lateral bead entire, rather thin; lateral groove crenulate at bottom, deep and narrow in basal half, barely wider and slightly more shallow in front. Inner basal sulci vestigial, almost indistinct yet long, running parallel to each other on basal two fifths, obliterate basally; basal sulcus, combined with a remnant of basal bead, as a rectangular impressed line separated by a fold from basal angle, this fold being as wide as lateral bead. Disc smooth, except for sparse, ill-defined transverse rugosities. Median line, transverse impressions and lateral setae as in previous species.

Elytra connate, elliptic, broadest medially, EW/EL 1.55, EW/ PW 1.20, apices rounded combined, preapical sinuation imperceptible, plica internal. Base slightly oblique, humeri rather widely rounded, humeral tooth just traceable as a minute tubercle between lateral bead and basal ridge; this latter reaching stria 1. Striae deep, minutely punctate before apex, otherwise nearly smooth, 10 th finely yet distinctly punctate in basal three fifths; striae 1–6 adjoining basal ridge; parascutellar striole missing. Intervals convex, slightly more so laterally and apically, 7 th, 5 th and 3 rd confluent apicad in succession and then joining 2 nd and 8 th; 1 st merging in lateral bead at sutural angle; 8 th costate and very narrow, subcarinate before preapical plica, as wide as 9 th and less than half as wide as 7 th. Reflexed lateral margin narrow, slightly broadened apicad and barely convex in apical third. Parascutellar seta near base of stria 2 in interval 2, discal setae missing, stria 7 with one preapical seta, anterior, distant far from apex; USS: 23–25.

Underside impunctate, except for mesepisternum moderately and densely punctate across middle. Prosternum with a shallow median impression in front of procoxae. Prosternal process in ventral view truncate, with rounded angles; in lateral view rectangular, rounded apically; inclination wide, barely concave between just traceable lateral beads, slightly constricted at middle; vertical and straight in lateral view. Abdominal lateral bead entire; sternite VII similar in both sexes.

Legs as in P. pseudoglymmiger sp.n., except for protibia with 5–6 spinules at apex of posterolateral edge; tarsomere 5 glabrous ventrally; apical setal brush of mesotibia triangular, more than one-row; and metatibia glabrous at outer margin.

Aedeagus ( Figs 17–18 , 23, 26 ): Median lobe geniculate; apex in dorsal view large, with sides barely diverging apicad, widely rounded apically. Right paramere moderately long, crescent, more curved at apex.

DISTRIBUTION. Known from the type locality only.

NAME. Refers to very deep frontal sulci.

HABITATS AND HABITS. The holotype specimen was collected by pitfall trap in a montane broad-leaved forest.

Figures

Figs 14–16. Dorsal habitus, holotypes: 14 — Pterostichus (Steropanus) securipenis sp.n; 15 — P. (S.) pseudoglymmiger sp.n.; 16 — P. (S.) fossifrons sp.n. Рис. 14–16. Габитус дорЗально, голотипы: 14 — Pterostichus (Steropanus) securipenis sp.n.; 15 — P. (S.) pseudoglymmiger sp.n.; 16 — P. (S.) fossifrons sp.n.

Figs 17–22. Aedeagus of Pterostichus (Steropanus) spp.: 17–18 — P. (S.) fossifrons sp.n.; 19–20 — P. (S.) securipenis sp.n.; 21–22 — P. (S.) pseudoglymmiger sp.n., median lobe with everted and inflated internal sac; 17–20 — median lobe; 17, 19, 21 — left lateral aspect; 18, 20, 22 — right lateral aspect. Scale bars: 1 mm. Рис. 17–22. Эдеагус Pterostichus (Steropanus) spp.: 17–18 — P. (S.) fossifrons sp.n.; 19–20 — P. (S.) securipenis sp.n.; 21–22 — P. (S.) pseudoglymmiger sp.n., среднЯЯ долЯ с вывернутым и раЗдутым внутренним меШком; 17–20 — среднЯЯ долЯ; 17, 19, 21 — слева; 18, 20, 22 — справа. МасШтаб: 1 мм.

Figs 23–29. Aedeagus of Pterostichus spp.: 23, 26 — P. (Steropanus) fossifrons sp.n.; 24, 27 — P. (S.) securipenis sp.n. (apical margin slightly damaged); 25, 28 — P. (S.) pseudoglymmiger sp.n., median lobe with everted and inflated internal sac; 29 — P. (Vietosteropus) kuznetsovi sp.n.; 23–25 — median lobe, ventral aspect; 26–28 — inside of right paramere. Scale bars: 1 mm. Рис. 23–29. Эдеагус Pterostichus spp.: 23, 26 — P. (Steropanus) fossifrons sp.n.; 24, 27 — P. (S.) securipenis sp.n. (апикальный край слегка обломан); 25, 28 — P. (S.) pseudoglymmiger sp.n., среднЯЯ долЯ с вывернутым и раЗдутым внутренним меШком; 29 — P. (Vietosteropus) kuznetsovi sp.n.; 23–25 — среднЯЯ долЯ? вентрально; 26–28 — праваЯ парамера, иЗнутри. МасШтаб: 1 мм.