Pterostichus (Steropanus) securipenis Fedorenko, 2020

Fedorenko, D. N., 2020, New taxa of Pterostichini (Coleoptera: Carabidae) from Vietnam, Russian Entomological Journal 29 (1), pp. 38-52 : 41-44

Pterostichus (Steropanus) securipenis Fedorenko , sp.n.

Figs 14 , 19–20 , 24, 27 .

MATERIAL. Holotype ♂ ( ZMMU), labelled: ‘ Vietnam, Quang Nam Prov[ince]., Nam Gian Distr [ict]., Song Thanh Nat [io]n[al]. Park , 15°33´48´´N / 107°23´22´´E, h= 1050 m, 23.IV–11.V.2019, leg. D. Fedorenko’. Paratype ♀ ( SIEE), same data, except for ‘ 15°33´48´´N / 107°23´22´´E, h=1050 m’ .

DIAGNOSIS. This species belongs to a species group defined by four derived characters, tarsomere 5 glabrous ventrally, frontal sulci very deep; pronotal lateral groove wide, deep and distinctly punctate, and elytral striae deep and punctate. The new species is distinguished from the other three species of the group, P. sulcatipennis Fedorenko, 2018; P. cavifrons Fedorenko, 2018; and P. alveolatus Fedorenko, 2018, by the elytral striae very coarsely punctate, two (vs. one) apical setae in interval 8, and a distinctive aedeagus, with very wide, securiform apex of median lobe. Besides, P. sulcatipennis and P. cavifrons are distinguishable in the pronotum not or indistinctly cordate, with sides not or barely sinuate in front of basal angles. P. sulcatipennis is larger ( BL > 15.8 mm), frontal sulci narrower and more shallow, and pronotal lateral groove narrower and finely punctate; P. cavifrons has pronotum smooth and mesotibia with a few additional setae just in front of one-row apical setal brush; P. alveolatus is distinctive in having elytral discal seta present (vs. missing in the other species).

DESCRIPTION. BL 12.5–12.8 mm. Body ( Fig. 14 ) shiny black, with pronotal lateral groove and elytral striae dull due to coarse microsculpture. Legs red (paratype) or reddish brown (holotype), antennae reddish brown, paler apically, maxillary and labial palps red. Dorsal microsculpture meshed, superficial isodiametric, more (holotype) or less (paratype) distinct on head, distinct and moderately transverse on pronotum; pronotal lateral groove with coarse microsculpture, consisting of slightly longitudinal meshes. Elytral microsculpture superficial, consisting of narrow transverse meshes along middle of elytral interval (costa), turning into increasingly oblique meshes toward striae, and becoming coarse, slightly longitudinal, meshes at bottom of striae, with admixture of isodiametric meshes in strial punctures. Clypeus and pronotum densely or sparsely micropunctate, respectively.

Head: Eyes dorsal, small and prominent; gena about a third as long as eye, meeting neck at very obtuse angle. Frontal sulci smooth, diverging basad, in form of extremely deep, slightly oblong pits anteriorly, less deep behind, disappearing just posterior to the level of anterior supra-ocular seta. Supra-ocular groove very deep, straight anteriorly. Labrum subsinuate apically, apical setae equidistant inter se. Antennae just reaching pronotal base.

Penultimate labial palpomere quadrisetose (two fixed setae at inner margin plus two additional latero-apical setae, dorsal and ventral), except for a minute apical seta at outer margin. Terminal labial palpomere triangular, a third as wide at apex as long at inner margin in both sexes.

Pronotum cordate, PW / PL 1.28–1.29, PW /HW 1.57– 1.58, broadest 1/3–2/5 from apex (PLw/ PL 0.33–0.39); sides evenly rounded, sinuate just in front of basal angles. Base sinuate medially, oblique towards obtuse and blunt basal angles, slightly wider than apex, PB/PA 1.11–1.13. Apex rather deeply sinuate, barely convex just inside apical angles, without apical bead; apical angles porrect, with blunt apices. Lateral bead entire, fairly thick all along, lateral groove deep, wide, nearly flat, moderately and densely punctate, distinctly wider than lateral bead in medial two quarters, extended inside base into a fine and deep line almost reaching inner basal sulcus. These sulci very deep, running parallel to each other in basal third, obliterate just in front of base; outer basal sulcus missing. Median line very deep, sulcate, crenulate at bottom, reaching base and almost reaching apex. Disc smooth, coarsely punctate at base, confluently within inner basal sulci, densely inside, with punctures not quite reaching median line; 1–2 punctures present outside basal sulcus. Anterolateral seta in lateral groove, posterolateral seta in basal angle.

Elytra connate, elliptic, broadest behind middle, EW/EL 1.59–1.60, EW/ PW 1.19–1.20, without preapical sinuation or internal plica; apices contiguous, apex otherwise slightly trilobed due to summit of apically confluent costae 2 to 7 projecting slightly apicad. Base narrow and oblique, humeri rounded, humeral tooth blunt and only traceable in posterodorsal view; basal ridge outside stria 3, with a vestige between striae 4 and 5; humeral angle very obtuse. Striae 1–9 deep, very coarsely punctate, in apical third with punctures increasingly deep and large apicad; striae 1 and 7 with apical two punctures in form of large and very deep foveae; striae 1– 6 adjoining basal ridge. Parascutellar striole missing. Intervals costate, 7 th, 5 th, 3 rd, 2 nd and 1st confluent apicad in succession and then merging into a vanished lateral bead; intervals 8 and 9 vanished before apex. Reflexed lateral margin subequally narrow throughout its length. Parascutellar setigerous pore at base of stria 2, discal setae missing, two preapical setae in interval 8; USS: 18.

Underside. Prosternum with a fairly deep median groove terminating in a very deep pit 2/5 from apical margin. Prosternal process in ventral view truncate, with fairly sharp angles; in lateral view rectangular and blunt; inclination wide, rounded in posterior view, slightly oblique and concave in lateral view. Abdominal lateral bead entire and conspicuous; sternite VII similar in both sexes. Mesepisternum coarsely and rather densely punctate in anterior half; metepisternum smooth or with a few coarse punctures.

Legs: profemur posteriorly trisetose, protibia barely dilated apicad, with three spinules at posterolateral edge, preapical spinule separate from two apical ones. Tarsi laterally neither carinate nor sulcate; tarsomere 5 glabrous ventrally. Protarsomeres 1–3 dilated and biseriately squamose ventrally in male; strongly dentate at apical angles in female. Mesotibia with a one-row apical setal brush.

Aedeagus ( Figs 19–20 , 24, 27 ): Median lobe arcuate. Apex conspicuously bent ventrad, oblique and very wide. Right paramere moderately long, subtriangular, with a narrow parallel-sided apex.

DISTRIBUTION. Known from the type locality only.

NAME. Refers to the securiform apex of aedeagus median lobe.

HABITATS AND HABITS. Holotype was hand collected and paratype taken by pitfall trapping in a broad-leaved monsoon forest.

COMMENTS. Apical setal brush of the mesotibia has not been mentioned in the redescription of Steropanus [ Fedorenko , 2018]. It is certain that the originally transverse and one-row setal brush ( P. securipenis sp.n., P. sulcatipennis , P. pseudoviolaceus Fedorenko, 2018, P. obliteratus Fedorenko, 2018, and P. fossifrons sp.n.) at first evolved into that with a few additional setae appeared just above it in P. glymmiger ( Andrewes, 1937) , P. pseudoglymmiger sp.n., and P. cavifrons , and then into triangular and plurisetose setal brush in P. aequus ( Andrewes 1937) , P. asulcatus Fedorenko, 2018, and P. boriskataevi nom.n. as the additional setae became multiple.

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.