Trechus saluki Belousov & Kabak, 2019

Belousov, Igor A. & Kabak, Ilya I., 2019, New species of the genus Trechus Clairville, 1806 from the Chinese Tien Shan (Coleoptera: Carabidae), Zootaxa 4679 (1), pp. 47-68 : 56-57

Trechus saluki Belousov & Kabak , sp. n.

( Figs. 10 , 13 )

Type material: Holotype: 1(1) ♂, “ China, Xinjiang, Narat Mt. R., Zhasylkol River (left tributary of Zanma River ), 2000–2350 m, 21.06.2001, Kabak I. leg.” [43º14´30´´ N / 83º40´05´´ E—43º13´30´´ N / 83º39´00´´ E] ( ZISP) { Fig. 22 : 12–13 }. Paratypes: 12(6) ♂♂, 11♀♀, collected with holotype ( MPU, BMNH, ZISP, ZSM, CAG, CAK, CBK, CJS, CVZ) ; 3(2) ♂♂, 1♀, “ China, Xinjiang, Narat Mt. R., Zhasylkol River (left tributary of Zanma River ), 2 km down bifurcation, 1700 m, 26.06.2001, Kabak I. leg.” [43º15´40´´ N / 83º40´40´´ E] ( IZAS, CBK) { Fig. 22 : 11}; 1(1) ♂, “ China, Xinjiang, Tashpa Mts, left bank of Kunges river , 8 km SW of Araltiube village, 2300–2600 m, 18.06.2001, Kabak I. leg.” [43º21´40´´ N / 83º41´45´´ E—43º21´00´´ N / 83º41´40´´ E] ( CBK) { Fig. 22 : 7}.

Description. Body short ovate, slightly constricted at pronotal base, convex ( Fig. 10 ). Appendages rather short. Upper-side brownish, pronotum, suture and margins of elytra usually paler, occasionally disc of elytra and head darkened. Legs concolorous, pale brownish. Antennae vaguely obscured beginning with apical part of segments 2–4. Head dark brownish, mouthparts and frons in middle a little paler.

Head proportionally small, eyes medium-sized and rather flat, tempora long and flat, sparsely but regularly pubescent. Frontal furrows evenly impressed, subangulate and approaching one another in middle. Supraorbital setae located in lines, approximately parallel to body axis, posterior seta far behind posterior margin of eye. Pores of both anterior and posterior supraorbital setae foveolate, though posterior one less markedly.

Pronotum robust, convex, markedly transverse, with maximum width in apical third. Its sides broadly arcuate anteriorly, straight or barely sinuate before hind angles, the latter obtusangular, more or less marked, usually blunt at apices. Posterior margin straight, slightly oblique or emarginate laterally; anterior margin straight or barely concave. Anterior angles rounded, though marked. Lateral margins bordered and narrowly reflexed, lateral groove regular for most of its length. Prebasal transverse impression gradually arcuate, deep and well-engraved, basal foveae small and shallow. Basal surface of pronotum sparsely longitudinally rugose. Apical transverse impression continuous. Anterior marginal seta located in anterior third of pronotum, posterior seta in hind angle. Median line distinct, becoming much deeper near basal margin.

Elytra broadly ovate, with sides evenly and broadly arcuate, widest near mid-length. Humeri prominent, though rounded, prehumeral margin markedly oblique, posthumeral sinuation faint. Elytral apex broadly rounded, with slight subapical sinuation. Striation of elytra rather shallow: only striae 1–3 distinct and continuous, others shallow and shortened, becoming less distinguishable toward sides. Striae 3 and 4 joining apically, stria 5 joining apical recurrent striole. Apical triangle slightly elongate, its inner side longest. Parascutellar striole and parascutellar pore present. All elytral striae slightly punctured.

Microsculpture distinct over entire body surface, consisting of isodiametric meshes on head, irregular and slightly transverse meshes on disc of pronotum, and distinctly transverse meshes on elytra.

Aedeagus ( Fig. 13 ) rather small and very thick, its apical part short, triangular in shape in dorsal view. Parameres short, nearly straight or slightly arcuate in apical half, left paramere clearly longer, with well-developed ventral apophysis; each paramere bearing 4 apical setae. Endophallus armature consisting of several complexly twisted plates and one scaly patch located near left wall of median lobe.

Sexual dimorphism. Males differ in larger body size (on average, 3.05 mm vs. 2.93 mm in females, p≤0.05) and proportionally larger elytra (EL/PL, on average, 2.99 vs. 2.84 in females; EL/EW, on average, 1.37 vs. 1.34 respectively, for both ratios p≤0.001; EW/HW, on average, 2.02 vs. 1.97 respectively, EW/PW, on average, 1.55 vs. 1.51 in females, p≤0.01 for both latter ratios).

Comparative notes. Doubtless T. saluki sp. n. is most closely related to T. kashensis Belousov & Kabak, 2001 and the two species can only be separated with confidence on the basis of the male genitalia: the aedeagus of the new species has a shorter apex, its endophallus armature is proportionally larger, with a more heavily sclerotized dorsal piece and more extended scaly patch ( Fig. 13 vs. Fig. 14 ). Externally T. saluki sp. n. differs in its larger size (on average, 3.0 mm vs. 2.9 mm in T. kashensis , p≤0.05), smaller eyes (means for YL/TL ratio: 1.73 vs. 2.22 in T. kashensis , p≤0.001), pronotum with basal margin approximately as wide as anterior margin (mean for ratio PB/PA: 1.01 vs. 1.07 in T. kashensis , p≤0.001) and preapical pore located distinctly behind umbilicate pore 8 (located at approximately the level of this pore in T. kashensis ).

Distribution. The species is known from the eastern part of the Narat Mountain Range and Tashpa mountains located between the valleys of the Kunges and Zanma rivers. The Kunges river seems to constitute a natural boundary between this species and the allied T. kashensis .

Bionomics. T. saluki sp. n. occurs in the forest zone at elevations between 1700 and 2550 m. Surprisingly this species was often found sifting from the litter of coniferous trees.

Derivatio nominis. We are pleased to name this species after our friend and colleague Mr. S.V. Saluk (Minsk).

Figures

FIGURE 10. Trechus saluki sp. n., habitus, male, paratype.

FIGURE 22. Collecting sites of Trechus species of the kashensis group. Red square—T. kashensis Belousov & Kabak, 2001; yellow square—T. saluki sp. n. Localities’ numbers—as in the “Material” section.

FIGURES 13–21. Male genitalia of Trechus spp. n., paratypes: a—lateral view, b—dorsal view. 13—T. saluki sp. n.; 14—T. kashensis Belousov & Kabak, 2001 (from Belousov & Kabak 2001); 15–17—T. aghiazicus sp. n.; 18–21—T. cratocephalus sp. n.