Pterostichus (Vietosteropus) subirideus, Fedorenko, 2023

Fedorenko, D. N., 2023, New taxa of Pterostichus (Coleoptera: Carabidae) from Vietnam, Russian Entomological Journal 32 (1), pp. 16-39 : 24-26

Pterostichus (Vietosteropus) subirideus Fedorenko, sp.n.

Figs 4 , 20–21 , 26, 33 , 41–42, 48.

MATERIAL. Holotype ♂ ( ZMMU) and five paratypes: 4♂♂, ♀ ( SIEE), labelled: ‘ Vietnam, Ha Tinh Prov [ince]./ Vu Quang nat[io]n[al]. Park ,/ Kim Quang env., h~ 200 m / 18°17´38´´N 105°22´06´´E / 24.V-1.VI.2022 / leg. D.Fedorenko’; paratype ♀ ( SIEE), with same label, except for h~ 440 m / 18°16´26´´N 105°21´41´´E. — The female paratype and a male paratype have damaged body parts as follows: the prothorax and the head or the left propleuron, combined with left antennomeres 9–11 and right antennomeres 6– 11 lost, respectively.

Aedeagus examined in four males, internal sac examined in one male.

DIAGNOSIS. With characters of the subgenus [ Fedorenko, 2017]. A representative of the dalatensis species group, recognizable by the combination of frontal sulci deep and diverging, pronotal lateral bead merged into a widely explanate lateral margin, and ti 3 with at least single lateral seta (vs. none in the other species of this group). Aedeagus, including internal sac and short right paramere, is distinctive, too.

DESCRIPTION. BL 12.3–14.1 mm. Body ( Fig. 4 ) shiny black, pronotum and elytra slightly iridescent; antennae, palps, protibiae and protarsi reddish brown. Dorsal microsculpture very superficial and thence hardly traceable, consisting of isodiametric meshes on head, moderately transverse meshes on pronotum, and very dense transverse lines on elytra; reflexed lateral margin of the latter with very coarse microsculpture, consisting of squamose to nearly granulate, isodiametric or slightly longitudinal meshes.

Eyes large and convex, genae very short and meeting neck at slightly obtuse angle. Clypeus barely sinuate at apical margin, frontoclypeal suture straight. Frons smooth, frontal sulci straight, smooth and deep, strongly diverging, as long as 3/5 distance between frontoclypeal suture and anterior supra-ocular seta, not extended onto clypeus and abruptly disappearing behind. Labrum rectangular, slightly transverse, slightly sinuate at apical margin. Mandibles smooth dorsally. Submentum quadrisetose.

Pronotum subcircular and rather flat; sides strongly and evenly rounded, broadest just in front of middle. Base truncate, subsinuate at middle; basal angles very obtuse and rounded, almost indistinct; inner basolateral sulci deep, barely diverging basad, running on about basal two fifths, not quite reaching base; outer sulcus in form of C-shaped extension of lateral groove, merging into slightly concave basolateral fovea at a distance from basal margin. Apex evenly sinuate between apical angles; these slightly projecting, right to obtuse and blunt; apical bead obliterate in about middle fourth. Explanate lateral margin flat, not or barely reflexed, moderately wide in front of anterolateral seta, wider behind. Lateral bead missing, lateral groove narrow and deep in apical three quarters, sparsely and finely punctate in apical third to half. Median line fine yet deep, obliterate basally and apically. Basal and apical transverse impressions indistinct. Base very sparsely punctate in basolateral foveae to impunctate, with 2–3 fine punctures at bottom of inner basolateral sulcus only.

Elytra oblong-oval, broadest at about middle, rounded on sides, less so in second to third sixth; humeri rounded; apices slightly separate and blunt; preapical sinuation moderately deep, preapical plica distinct in lateral view. Base rather narrow, humeral tooth indistinct or almost so; basal ridge slightly concave, slightly higher at obtuse humeral angle than at scutellum. Striae deep and impunctate, stria 7 outside humeral angle; parascutellar striole missing. Intervals convex, very so toward apex and toward lateral margin, intervals 7, 5 and 3 merging preapically in succession; intervals 7 and 8 subequally wide. Discal seta d2 slightly behind middle, D2/ EL 0.53–0.59 (0.57). Stria 7 with two proximate preapical setae. USS: 17–18, continuous.

Ventral side nearly smooth or mesepisterna moderately punctate, combined with metepisterna and sides of abdominal sternites II–IV sparsely punctate or very so. Prosternal process in dorsal view with apex truncate or slightly concave, without apical bead, in lateral view obtuse and rounded; inclination wide, subconvex, with lateral edges very blunt. Lateral abdominal bead entire. Abdominal sternite VII with setae adjoining this bead in female while about 1/3 sternite length distant from apex in male.

Legs: fe 3 with single, proximal, seta (one female and one male have either vestigial distal seta or ‘setigerous’ pores lacking setae, respectively); ti 3 with 1–2 lateral setae.

Aedeagus ( Figs 20–21 , 26, 33 , 41–42, 48): apex of median lobe lamellate and straight in lateral view, obtrapezoidal and fairly large in dorsal view. Right paramere triangular and short. Everted and inflated internal sac in dorsal view bent ventrad only, with right preapical bulb small and two apical sclerotized vesicles, av1 and av3; left preapical bulb large, with four vesicles, lv1 very small, lv2 and lvi large, and lv3 well-developed [for the abbreviations see Fedorenko, 2017].

DISTRIBUTION. Known from the type locality only.

NAME. Refers to a more or less distinct iridescence of the elytra.

HABITATS AND HABITS. All the specimens were hand collected in a montane, tropical, monsoon forest at the lowest altitudes for the subgenus.

Figures

Figs 1–5. Dorsal habitus: 1 — Pterostichus glabellus sp.n., paratype ♀; 2 — P. unisetosus sp.n., holotype; 3 — P. primitivus sp.n., holotype; 4 — P. subirideus sp.n., paratype ♂; 5 — P. batdaiensis sp.n., paratype ♂ from Sa Pa env. Рис. 1–5. Габитус дорЗально: 1 — Pterostichus glabellus sp.n., паратип ♀; 2 — P. unisetosus sp.n., голотип; 3 — P. primitivus sp.n., голотип; P. subirideus sp.n., паратип ♂; 5 — P. batdaiensis sp.n., паратип ♂ иЗ окрестностей Sa Pa.

Figs 12–21. Aedeagus median lobe: 12–13 — Pterostichus glabellus sp.n.; 14–15 — P. unisetosus sp.n.; 16–17 — P. tonkinensis; 18– 19 — P. austrinus sp.n.; 20–21 — P. subirideus sp.n.; 12, 14, 16, 18, 20 — left lateral aspect; 13, 15, 17, 19, 21 — right lateral aspect. Scale bars 1 mm. Рис. 12–21. СреднЯЯ долЯ Эдеагуса: 12–13 — Pterostichus glabellus sp.n.; 14–15 — P. unisetosus sp.n.; 16–17 — P. tonkinensis; 18– 19 — P. austrinus sp.n.; 20–21 — P. subirideus sp.n.; 12, 14, 16, 18, 20 — слева; 13, 15, 17, 19, 21 — справа. Масштаб 1 мм.

Figs 22–34. Aedeagus: 22, 30 — Pterostichus glabellus sp.n.; 23, 31 — P. unisetosus sp.n.; 24, 32 — P. tonkinensis; 25, 28–29 — P. austrinus sp.n.; 26, 33 — P. subirideus sp.n.; 27, 34 — P. laevibasis sp.n.; 22–26 — median lobe; 28–34 — right paramere, scale as for respective median lobe; 22–25, 27 — ventrobasal aspect; 29–34 — left lateral aspect; 26, 28 — dorsal aspect. Scale bars 1 mm. Рис. 22–34. Эдеагус: 22, 30 — Pterostichus glabellus sp.n.; 23, 31 — P. unisetosus sp.n.; 24, 32 — P. tonkinensis; 25, 28–29 — P. austrinus sp.n.; 26, 33 — P. subirideus sp.n.; 27, 34 — P. laevibasis sp.n.; 22–26 — среднЯЯ долЯ; 28–34 — праваЯ парамера в масштабе соответствуюЩей средней доли; 22–25, 27 — вентробаЗально; 29–34 — слева; 26, 28 — сверху. Масштаб 1 мм.