Trechus suopoensis, Belousov & Kabak, 2020

Belousov, Igor A. & Kabak, Ilya I., 2020, New Trechus species of the kozlovi group from Sichuan (Coleoptera: Carabidae), Zootaxa 4786 (4), pp. 451-484 : 453-456

Trechus suopoensis sp. n.

( Figs 1, 2–4 )

urn:lsid:zoobank.org:act:6DA1759D-65BD-45C7-A5E9-31186EEAE529

Type material: Holotype: 1(1) ♂, “ China, C. Sichuan, E Danba, S Guanyongchang, 30º53´11´´N / 102º02´39´´ E— 30º52´59´´N / 102º03´24´´ E, 4450–4850 m, 13.08.2004, Belousov I. & Kabak I. leg.” ( ZISP) . Paratypes: 65(9) ♂♂, 32♀♀, collected with holotype ( IZAS, MPU, BMNH, SMNS, ZISP, ZSM, CAG, CAK, CBK, CDW, CJS, CVZ) ; 48(14) ♂♂, 23(2) ♀♀, “ China, C. Sichuan, E Danba , E of Suopo, 30º52´54´´N / 102º03´05´´ E— 30º52´46´´N / 102º03´34´´ E, H= 4560–4780 m, 14.08.2004, Belousov I. & Kabak I. leg.” ( ZISP, ZSM, BMNH, CAG, CBK) ; 2(2) ♂♂, 2♀♀, “ China, C. Sichuan, E Danba, SE Mt Gema, bas. Hanniuhe River, N Chengducun Village , 30º52´41´´N / 102º04´22´´ E, H= 4615 m, 15.08.2004, Belousov I. & Kabak I. leg.” ( CBK) .

Description. Body rather short-oval, moderately constricted at pronotal base, subconvex, depressed on disc of elytra and along their suture ( Fig. 1). Appendages of average length. Upperside mostly dark brown; base, anterior portion and margins of pronotum (occasionally whole pronotum), suture and margins of elytra distinctly paler, reddish. Legs uniformly yellowish brown. Head behind clypeus darker. Antennae vaguely obscured from segments 4–5, more seldom, from segment 3. Maxillary palpi, except for last segment, slightly obscured.

Head of average size, flattened on disk, eyes medium-sized and convex, tempora rather long and slightly to moderately convex, more distinctly in posterior third, sparsely and shortly pubescent. Frontal furrows regularly impressed, arquate, approaching each other in median portions. Supraorbital setiferous pores located in lines parallel to body axis, posterior seta—far behind posterior margin of eye. Anterior pore markedly impressed, foveolate, posterior one shallowly impressed.

Pronotum slightly convex, markedly transverse, subcordate, distinctly constricted at base, with maximum width in apical third. Its sides broadly arcuate in anterior part, with long and shallow sinuation before hind angles, the latter of medium size, subrectangular, more or less acute apically, slightly produced outwards. Posterior margin straight; slightly concave near basal foveae and subconvex at sides; anterior margin concave, occasionally nearly straight.Anterior angles rounded, barely prominent. Lateral groove of medium width, markedly expanded posteriorly, margins slightly reflexed. Prebasal transverse impression not sharply engraved (often split into a few longitudinal foveae), bent near basal foveae, rather deep. Basal foveae large and deep, adjoining lateral groove. Apical transverse impression distinct laterally, becoming shallower medially. Anterior marginal seta placed in about anterior third of pronotum, posterior seta at hind angle. Base of pronotum coarsely longitudinally rugose. Median line moderately impressed, deepest near basal margin, slightly surpassing the preapical transverse impression anteriad.

Elytra short-oval, flattened on disk, widest near their middle, with sides evenly and slightly arcuate. Humeri marked, though broadly rounded, elytra wider at level of preapical sinuation than at humeral level. Each elytron slightly sinuate and separately rounded at apex. Elytral striation moderately deep, striae rather regular, outer shallower, though even stria 7 visible in its median portion, all striae usually rather straight, occasionally slightly waved. Inner interspaces, at most, subconvex, others flat, all interspaces subequal in width except for interspace 1, which is much narrower, and interspace 2 markedly dilated in posterior portion. While striae deeply engraved, interspace 8 nearly twice as wide as interspace 9. All elytral striae finely punctured. The two most common types of striation on the apical slope are as follows: ((2x3)x4)((5x6)x7)xAS or ((2x(3x4)((5x6)x7)xAS. However, apical striole may be connected to any of striae 5–7. Normally, apical striole evenly curved, deeper in its posterior portion, gradually shallowing and becoming straighter in its anterior portion. Parascutellar striole well engraved. Apical triangle markedly elongate, its inner side nearly parallel to body axis. Distance from angulo-apical pore to preapical one is twice as long as that from angulo-apical pore to exterior pore. Preapical pore located clearly on interspace 3 at level of anterior termination of apical carinula, much more rarely it may be located in stria 2, in this case interspace 2 markedly widened in posterior portion. Lateral groove of elytra average, margins reflexed. Basal portion of lateral border reaching anterior termination of stria 4 anteriorly.

Microsculpture markedly developed over entire body surface, consisting of isodiametric meshes on head, less regular, more transverse meshes on disc of pronotum, nearly isodiametric on its base and near preapical impression and consisting of markedly transverse meshes on elytra. All upper surface micropunctured, glabrous.

Front tibiae without trace of longitudinal groove, glabrous on their anterior surface. Two basal segments of anterior tarsi markedly dilated in male, each with massive inner tooth and adhesive appendages beneath.

Shape of aedeagus, especially its lamella rather variable, ( Figs 2–4 ). Median lobe of medium size, curved at basal third and nearly straight in distal half, ventral side faintly emarginate before apical portion, apex rather variable, usually slightly dilated in lateral view. Viewed dorsally, the median lobe slightly and gradually narrowed toward the apex, rounded apically. Basal orifice moderately emarginate. Sagittal lobe small to medium. Parameres rather long and narrow, slightly arcuate in their distal part, truncate apically, each bearing 4 apical setae. Left paramere clearly longer, with a well-developed ventral apophysis. Endophallus armature consisting of two slightly sclerotized pieces located near left wall of median lobe. Proximal piece larger, ovate in lateral view, spreading along ventral, left and dorsal walls of median lobe. Distal piece smaller and oblong.

Sexual dimorphism. Males differ in larger body size (on average, 3.12 mm vs. 2.99 mm in females, significance level p≤0.01), proportionally longer elytra (EL/EW, on average, 1.35 vs. 1.33 in females, p≤0.05) and longer antennae (EL/AL, on average, 1.18 vs. 1.20 in females, p≤0.05).

Comparative notes. In both the external and genitalia characters, the new species is similar to T. kaznakovi Jeannel, 1935 . It differs, though, from the latter species in the pronotum with wider lateral groove and in the aedeagus lacking large apical disk ( Figs 2–4 vs. Figs 15–16 in Belousov & Kabak, 2000).

Compared to the species described in the present paper, T. suopoensis sp. n. is most similar to T. maoniu sp. n. Their differences are considered below.

Distribution. The species is found on northern and southern slopes of Mount Gema, east of Suopo Village (Sichuan). On the southern slopes, it co-exists with T. gemaensis sp. n.

Bionomics. Occurring in alpine meadows at elevations of 4450–4850 m.

Derivatio nominis. The species name derives from the toponym “Suopo”, a small village located not far from the type locality of the species.

Figures

FIGURES 2–4. Male genitalia of Trechus suopoensis sp. n., paratypes: a—lateral view, b—dorsal view, c—dorsal view at a right angle to apical lamella.