Tarsagonum (Louwerensium) breve, Gildenkov, 2020

Fedorenko, D. N., 2020, New species of Meleagros and Tarsagonum (Coleoptera: Carabidae: Platynini) from the Oriental region, Russian Entomological Journal 29 (2), pp. 139-147 : 145-146

Tarsagonum (Louwerensium) breve

Fedorenko , sp.n.

Figs 5 , 11–13 .

MATERIAL. Holotype ♂ ( ZMMU): ‘ Central Laos, near Vang Vieng vill., 18–22.VIII.2005, leg. A.Sokolov’.

DESCRIPTION. BL 9 mm. Body ( Fig. 5 ) black, a little shiny, legs rather dark brown, with knee and tibiae toward apices slightly reddish; antennae, tarsi and mouthparts rather pale reddish brown, mandibles toward apices and antennal scape slightly infuscated. Microsculpture distinct, rather coarse, consisting of isodiametric meshes on head, superficial at middle of both clypeus and neck, obliterate on sides of clypeus and neck; pronotal and elytral microsculpture more superficial. consisting of small, moderately or very transverse meshes, respectively.

Head: Eyes hemispherical, small, protruding, and dorsolateral owing to supra-ocular groove being very deep and posteriorly reaching posterior margin of eye; genae long, GL/ OL 0.88, very slightly oblique, nearly straight behind eyes, increasingly convex toward and meeting neck at obtuse angle; neck constriction deep laterally, more shallow medially. Frontal foveae sulciform, s-shaped, fairly deep and long, barely surpassing the level of anterior supra-ocular seta; posterior seta closer to neck constriction than to eye. Frons between eyes with a shallow round pit.

Pronotum barely wider than long, PW/PL 1.08, a fourth wider than head, PW/HW 1.25, broadest two fifths from apex PLw/PL 0.42; base slightly convex and slightly broader than truncate apex, PB/PA 1.15. Sides very convex in apical half, indistinctly angulate at lateral seta, converging and straight behind, slightly diverging in basal fourth. Basal angles right and pointed, apical angles adherent to neck, very obtuse but a minute blunt tooth. Lateral bead conspicuous, fine, very so apically; lateral groove narrow, deep and uneven in basal two thirds; basal bead missing; apical bead well-developed at apical angles only, otherwise obliterate. Median line very deep and crenulate, reaching base, obliterate apically. Basal and apical transverse impressions deep, the latter interrupted just medially. Basal foveae reaching the level of lateral setae, almost reaching basal margin, diverging on each side of basal transverse impression. Disc smooth, base posterior to basal transverse impression, apex in front of and including apical transverse impression, and lateral groove except apically coarsely and more or less densely punctate to somewhat rugose-punctate.

Elytra short and wide, EL/EW 1.43, EW/PW 1.78, nearly parallel-sided, broadest just behind middle, rounded apically combined, with extreme tips blunt, no preapical sinuation; humeri square yet widely rounded; sides slightly concave a third from base. Basal ridge obliterate inside stria 5 (inside stria 4 in dorsal view). Striae coarsely punctate in basal third, smooth behind.

Underside: prosternal process rather short, with entire marginal bead; its apex rounded in lateral view, except for a minute tubercle at tip; inclination carinate in posterolateral view.

Legs: Profemur without postero-apical seta, metatrochanteral seta present.

Aedeagus ( Figs 11–13 ): median lobe in ventral view rather narrow apically, with right margin concave preapically. Internal sac with two dorsolateral teeth, right tooth medi- an, very large and long, left one preapical and rather small.

DIAGNOSIS. The species is distinctive chiefly in having short subquadrate elytra and the head square owing to nearly parallel-sided genae, with the eyes small and very convex. Aedeagus is distinctive, too.

NAME. Refers to a robust habitus of the species, including short elytra.

GEOGRAPHIC DISTRIBUTION. Known from the type locality only, Vientiane Province, Laos .

Figures

Figs 4–6. Dorsal habitus of holotypes: 4 — Meleagros astericollis sp.n.; 5 — Tarsagonum (Louwerensium) breve sp.n.; 6 — T. (L.) indicum sp.n. Рис. 4–6. Габитус голотипов, дорЗально: 4 — Meleagros astericollis sp.n.; 5 — Tarsagonum (Louwerensium) breve sp.n., holotype; 6 — T. (L.) indicum sp.n.

Figs 7–16. Median lobe of aedeagus in holotypes: 7, 9 — Meleagros laticeps sp.n.; 8, 10 — M. pseudosinicola sp.n.; 11–13 — Tarsagonum (Louwerensium) breve sp.n.; 14–16 — T. (L.) indicum sp.n.; 7, 8, 11, 15 — left aspect; 9–10, 13–14 — ventral aspect; 12, 16 — right aspect. Scale bars: 0.5 mm. Рис. 7–16. СреднЯЯ долЯ Эдеагуса голотипов: 7, 9 — Meleagros laticeps sp.n.; 8, 10 — M. pseudosinicola sp.n.; 11–13 — Tarsagonum (Louwerensium) breve sp.n.; 14–16 — T. (L.) indicum sp.n.; 7, 8, 11, 15 — слева; 9–10, 13–14 — вентрально; 12, 16 — справа. Масштаб: 0,5 mm.