Trigonaptus inaequalis, Fedorenko, 2020

Fedorenko, D. N., 2020, New taxa of Pterostichini (Coleoptera: Carabidae) from Vietnam, Russian Entomological Journal 29 (1), pp. 38-52 : 50

Trigonaptus inaequalis Fedorenko, sp.n.

Figs 31 , 44–48, 50, 52.

MATERIAL. Holotype ♂ ( ZMMU), labelled: ‘S Vietnam, Lam Dong Prov [ince]., Bi Doup-Nui Ba [Nature] Reserve , 12°07´N / 108°39´20´´E, Bi Doup Mt. , N [orthern] slope, h= 1700–1900 m, 10.IV.2008, leg. D.Fedorenko’ . Paratypes 3♂♂ ( SIEE), same data except 15–16. or 19–22.IV.2008 .

DIAGNOSIS. Medium-sized species recognizable in body black; forebody with slight violaceous lustre; eyes prominent; clypeus truncate apically; frontal sulci long, each with an oblong tubercle running between supraocular setae just inside the sulcus; pronotal lateral edge crenulate; elytral intervals 3, 5 and 7 distinctly to much wider than others; metatrochanter apically pointed, etc.

DESCRIPTION. BL 14.7–16 mm, body ( Fig. 31 ) black and slightly dull. Head and pronotum with slight violaceous lustre, elytra laterally with imperceptible bronzed reflections. Knees and tarsi deep reddish brown; antennomeres 1–4 dark brown, their bases, antennomeres 5–11, and palps red. Sides of labrum translucent with red. Dorsum densely microscopically punctate, meshed microsculpture distinct, consisting of very small meshes, isodiametric on head, isodiametric or barely transverse on pronotum, slightly transverse, with admixture of isodiametric meshes, on elytra.

Head incrassate, large, together with closed mandibles about a fourth longer than pronotum, without neck constriction. Gena half as long as small and prominent eye; eyes lateral and slightly dorsal, with very deep supraocular groove just inside. Clypeus truncate apically, frontoclypeal suture hardly traceable, barely convex basad, with a shallow median pit and a deeper one on each side. Frontal sulci long, very deep and impunctate, slightly S-shaped in front the level of anterior supraocular setae, then forking; forks running nearly parallel to each other, outer fork adjoining while inner fork curved towards and disappearing just inside posterior supra-ocular seta; a conspicuous oblong tubercle between them. Frons on each side behind clypeus with a small and fairly deep pit, between eyes with seven short and shallow striae. Neck laterally with a small deep pit behind eye; sides of head dorsal to gular sutures coarsely transversely rugose. Antennae reaching basal 2/5 pronotum.

Labrum evenly sinuate between slightly pointed angles; distances between three apical setae on each side, inner, intermediate, and lateral, ca. 0.7:1. Mandibles with ventral scrobal ridge shallowly sinuate anteriorly and thence obtusely angulate basally. Mentum tooth slightly bifid, pits rather deep yet rudimentary, without openings. Submentum basally with a very deep groove between gular sutures. Terminal labial palpomere half as wide at apex as long at inner margin.

Pronotum subcordate, PW / PL 1.24–1.33 (1.29, n=4), PW /HW 1.47–1.53 (1.49), broadest two fifths from apex, PLw/ PL 0.39–0.43 (0.41); sides rounded, indistinctly sinuate in front of obtuse and blunt basal angles; lateral edge slightly crenulate. Base truncate, as wide as apex, PB/PA 0.97–1.01 (0.99), its sides lateral to inner basal sulci gently oblique and barely sinuate. Apex truncate, apical angles slightly acute and a little projecting; apical bead obliterate except in lateral sixth. Reflexed lateral margin costate, bead-like, slightly broadened basad. Basal foveae rather deep, inner and outer basal sulci moderately deep and nearly smooth, outer running on basal third, inner barely longer yet anteriorly forking or extended directly into a shallow sublateral line that almost reaching apex.

Elytra rather short, EW/EL 1.54–1.57 (1.55), EW/ PW 1.19–1.23 (1.22), with a fairly deep impression across bases of intervals 3–5. Humeri distinct. Basal ridge inwardly reaching stria 3, humeral angle very obtuse. Striae deep, finely to moderately punctate, stria 9 coarsely punctate; parascutellar striole vestigial, very short. Stria 1 subinterrupted anteriorly (i.e., not quite fused to primary parascutellar striole), 1–6 or 4–6 uneven apically and obliterate just before apex, with 5 th and 6 th mostly confluent and abruptly disappeared a fifth from apex; stria 6 anteriorly opposite humeral angle. Intervals subconvex, 3 rd, 5 th and 7 th much wider than others; 7 th very convex before and behind; 8 th very narrow, subcarinate in basal three fifths, carinate behind. USS: 18–19.

Underside densely, in part confluently punctate, abdominal sternites II– VI with clusters of dense punctures. Mesoventrite with a fine ridge in front of mesocoxae. Metepisternum as long as wide. Abdominal transverse sulci obliterate medially, sometimes sternite VII with transverse sulcus traceable throughout.

Metatrochanter apically pointed and adherent to metafemur. Meso- and metatarsomeres 1/2/3 with 3–4/2/1 anterolateral setae, respectively.

Aedeagus (Figs 44–48): median lobe slightly geniculate, with apex very narrow, in dorsal view barely curved to the left and slightly capitate; right paramere very short and rounded apically. Internal sac (Figs 50, 52) with proximal bulb small and distinct in right lateral view only.

NAME. Refers to the elytral intervals of unequal width.

DISTRIBUTION. Known from the type locality only.

HABITS AND HABITATS. All specimens were hand collected in a monsoon broad-leaved forest.

Figures

Figs 30–32. Dorsal habitus, holotypes: 30 — Pterostichus (Vietosteropus) kuznetsovi sp.n.; 31 — Trigonaptus inaequalis gen. et sp.n.; 32 — T. longiscapus sp.n. Рис. 30–32. Габитус дорЗально, голотипы: 30 — Pterostichus (Vietosteropus) kuznetsovi sp.n.; 31 — Trigonaptus inaequalis gen. et sp.n.; 32 — T. longiscapus sp.n.