Trichotichnus (Bottchrus) baglungensis, Schmidt, 2017

Schmidt, Joachim, 2017, Brachypterous ground beetles of the Trichotichnus subgenus Bottchrus Jedlička (Coleoptera, Carabidae) from the Himalaya, with description of fifteen new species, Zootaxa 4323 (3), pp. 301-358 : 308-310

Trichotichnus (Bottchrus) baglungensis sp. n.

(Figs 2, 14–21, 151, 2)

Type material. Holotype: ♂, “ NEPAL Baglung Lekh , W Pokhara, 10–15 km NW Baglung, 2350–2550 m, leg. Schmidt 10– 12.5.2004, 28°18'36"N 83°31'56"E ” (cJS).

Paratypes: 4 ♂, 2 ♀, same data as holotype (cJS, ZIN) ; 1 ♂, “ NEPAL Baglung Lekh , ca. 30 km W Baglung, N Tara Khola 25–2700 m, 18.5.2004, leg. J. Schmidt, 28°22'N / 83°20'E ” (cJS).

Description. Habitus as in Fig. 2. Body length 5.4–5.9 mm, width 3.1–3.5 mm.

Colour: Body piceous, shiny on dorsum, with light, but distinct bluish or greenish tinge on elytra; labrum, in most specimens also base of mandibles, very narrow margins of pronotum and apical portion of elytral margins as well as of elytral epipleurae paler, reddish brown; palpi, antennae and legs brownish yellow, with femora more or less distinctly infuscate.

Head: Large, with wide neck (in males, HWmax/PWmax = 0.72–0.74, HWmin/PWmax = 0.58–0.65; in females, these indices 0.73 and 0.57–0.62, respectively). Eyes moderately convex (in males, HWmax/HWmin = 1.14–1.27, and in females, 1.17–1.27), in lateral view broad oval, almost round. Tempora comparatively long, about half as long as eye, convex, somewhat abrupt to neck. Genae wide, about twice as wide as width of antennomere 1, with few short setae. Lateral margin of head between antenna and eye slightly protruded laterally, forming an obtuse angle near eyes, distinctly bordered. Area between supraorbital furrow and upper margin of eye wide, approximately as wide as width of antennomere 2 basally. Supraorbital setigerous pore located just behind of level of posterior margin of eye, separated from supraorbital furrow by width of antennomere 3 apically. Labrum moderately concave anteriorly. Clypeus slightly emarginate along anterior margin, moderately convex basally, flatly sloped to apex. Frons and vertex convex. Mentum and submentum completely fused, submentum with one long seta on each side (Fig. 14). Left mandible not truncate, blunted at apex. Dorsal microsculpture visible only laterally behind eyes, consisting of a mixture of transverse and almost isodiametric meshes. Antennae short, extending to the basal fifth of pronotum, with antennomeres 4–8 slightly longer than wide.

Pronotum: Slightly transverse (PWmax/PL = 1.35–1.45), widest slightly before the end of anterior third, markedly narrowed posteriad (PWmax/PWmin = 1.17–1.25), with one lateral seta inserted slightly before widest point. Sides almost straight, at most slightly sinuate in posterior third. Apical margin very slightly emarginate, bordered only laterally. Apical angles widely rounded, not protruded anteriad. Basal margin very broadly rounded or nearly straight medially and slightly oblique laterally, vaguely bordered only at basal angles, somewhat longer than apical margin and markedly shorter than base of elytra between humeral angles. Basal angles obtuse, each with a sharp (denticulate or subdenticulate) apex slightly protruded laterad. Pronotal disc convex, strongly sloped to apical angles, not depressed basally, slightly flattened at basal angles. Lateral gutter very narrow, not widened apically or basally. Median line distinct, ended before apical and basal margins. Basal foveae and lateral depressions absent; occasionally basal foveae present, but poorly delimited, small, elongate and very shallow. Surface sparsely, somewhat coarsely and irregularly punctate only along base and in latero-basal area. Microsculpture obliterate, usually present only along sides and at base laterally, occasionally indistinct meshes recognizable on disc.

Elytra: In lateral and caudal view convex, in dorsal view oval, relatively wide (in males, EL/EW = 1.27–1.37; EL/PL = 2.33–2.46; EW/PWmax = 1.25–1.34; in females, these indices 1.29–1.38, 2.30–2.41, 1.27–1.32, respectively), widest slightly behind middle, with somewhat acute apex. Humeri prominent, angularly rounded at tip, either without denticle or in some specimens with a very small denticle visible in caudal view. Subapical sinuation very shallow. Sutural angle somewhat sharp, in some specimens blunted or very narrowly rounded at tip. Basal edge evenly sinuate, forming a very obtuse angle with lateral margin. Striae evenly impressed along entire length. Parascutellar setigerous pore present, large. Parascutellar striole short, at most as long as distance from parascutellar pore to suture, with apex free or connected with stria 1. Intervals somewhat flat throughout, at most very slightly convex apically, weakly narrowed posteriad. Interval 3 with a discal setigerous pore at stria 2 behind middle. Marginal umbilicate series widely interrupted at middle, with 6–8 pores in anterior group and 7–9 pores in posterior group. Microsculpture strongly obliterate, indistinct on disc, with fine transverse meshes at apex and on two or three lateral intervals.

FIGURES 14–21. Trichotichnus (Bottchrus) baglungensis sp. n. (14–15, 20–21, paratypes; 17–19, holotype). 14, labium; 15, left metepisternum; 16, left laterotergite; 17, 19, median lobe of aedeagus; 18, terminal lamella and apical capitulum of aedeagus; 20, apex of last (VII) abdominal sternite, male; 21, same, female. 14–16, 20, 21, ventral view; 17, lateral view; 19, dorsal view; 18, caudal view. Scale bars = 0.25 mm (A: Figs 15–17, 19–21; B: Fig. 18).

Hindwings: Reduced to tiny scales.

Ventral surface: Prosternum and metasternum finely pubescent. Metepisternum (Fig. 15) almost as long as wide, strongly narrowed posteriad. Apex of last visible (VII) abdominal sternite subtruncate in male (Fig. 20) and rounded in female (Fig. 21).

Legs: Protibia without longitudinal sulcus on upper surface. Profemur with two to four setae on anterio-ventral margin. Tarsi short, metatarsus noticeably shorter than HWmin, with metatarsomeres markedly widened posteriad, metatarsomere 1 approximately as long as metatarsomeres 2+3. Tarsomere 5 with two pairs of ventro-lateral setae. In male, pro- and mesotarsi weakly widened.

Female genitalia (Fig. 16): Laterotergite (hemisternite) symmetrical, with three thick setae apically. Basal stylomere with one preapical spine on external margin. Apical stylomere moderately curved, with a peg-like spine at both ventral and dorsal edges of outer margin.

Male genitalia: Median lobe of aedeagus (Figs 17–19) in lateral view evenly arcuate, C-shaped, in dorsal view only slightly curved, almost straight, narrowed to apex in distal third. Terminal lamella moderately long, slightly narrowed to apex, distinctly sinuate at sides just before apical capitulum. The latter in lateral view (Fig. 17) oblique, with acute dorsal flange located less distally than rounded ventral flange; in caudal view (Fig. 18) somewhat triangular, very narrowly rounded at tip and with sides slightly rounded. Internal sac without spines, with a characteristic pattern of folders and spiny patches, particularly in basal portion of median lobe.

Etymology. The specific name refers to the mountain range, Baglung Lekh, where the type series was found.

Comparison. In habitus and penis structure very similar to T. (B.) holzschuhi . Both the species also share many other characters in common, e.g., mentum completely fused with submentum, humerus without denticle, metepisternum short and protibia dorsally not sulcate. Trichotichnus (B.) baglungensis sp. n. is distinguished from T. (B.) holzschuhi by having, at an average, a slightly smaller body size (5.4–5.9 mm versus 5.6–6.2 mm), the head relatively larger (HWmax/PWmax = 0.72–0.74 and HWmin/PWmax = 0.57–0.65 versus 0.64–0.71 and 0.56–0.59, respectively), the pronotal apical angles more widely rounded and not projecting anteriad, the pronotal lateral gutter narrow throughout, not widened in the apical third, the last visible (VII) abdominal sternite in male subtruncate at apex, and the dorsal microsculpture less distinct, particularly on the pronotal disc and inner intervals of elytra. In addition, there are distinct differences between these two species in the aedeagi (Figs 17–19 and 5–9, 11): in T. (B.) baglungensis sp. n. the terminal lamella of the median lobe is more markedly sinuate at sides, the apical capitulum is triangular, and the internal sac lacks the post-medial groups of small spines and is characterized by different patterns of spiny patches.

Distribution ( Fig. 151 , 2). Baglung Lekh mountain range in western Central Nepal, Baglung District, at altitudes of approximately 2350–2700 m.

Figures

FIGURE 151. Distribution of the Himalayan species of Trichotichnus subgenus Bottchrus. 1, T. holzschuhi Kirschenhofer, 1992; 2, T. baglungensis sp. n.; 3, T. parvulus sp. n.; 4, T. bubsaensis sp. n.; 5, T. schawalleri sp. n.; 6, T. obliquebasalis sp. n.; 7, T. panchhaseensis sp. n.; 8, T. siklesensis sp. n.; 9, T. pusillus sp. n.; 10, T. ganeshensis sp. n.; 11, T. minutus sp. n.; 12, T. cyanescens Ito, 1998; 13, T. martensi sp. n.; 14, T. opacus Ito, 1998.