Trichotichnus (Bottchrus) parvulus, 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 : 310-312

Trichotichnus (Bottchrus) parvulus sp. n.

(Figs 3, 22–31, 151, 3)

Type material. Holotype: ♂, “ NEPAL Annapurna , Mt. Panchhase, 2000–2300 m, W Pokhara, 18.5.97, lg. Schmidt ” (cJS).

Paratypes: 1 ♂, 8 ♀, same data as holotype (cJS, ZIN) ; 2 ♀, “ NEPAL Annapurna Krapa Danda 1800 m 26.5.97 /Schmidt” (cJS).

Description. Habitus as in Fig. 3. Body length 4.8–5.4 mm, width 2.1–2.4 mm.

Colour: Similar to that of the preceding species, but in most specimens femora not infuscate and in many specimens pronotal and elytral epipleurae reddish brown.

Head: Comparatively large, with wide neck (in males, HWmax/PWmax = 0.67–0.72, HWmin/PWmax = 0.56– 0.57; in females, these indices 0.70–0.74 and 0.57–0.61, respectively). Eyes very moderately convex (in males, HWmax/HWmin = 1.18–1.28, and in females, 1.18–1.26), in lateral view very wide oval, almost circular. Tempora one third to half as long as eye, somewhat flat or slightly convex, sloped to neck. Genae slightly or noticeably wider than width of antennomere 1, with few short setae. Lateral margin of head between antenna and eye, like in the preceding species, 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 level of posterior margin of eye, separated from supraorbital furrow approximately by width of antennomere 3 apically. Labrum moderately concave anteriorly. Clypeus almost straight, only slightly emarginate along anterior margin, moderately convex basally, flatly sloped to apex. Frons and vertex convex. Mentum and submentum ( Fig. 22 ) separated by transverse suture medially and fused laterally, submentum with one long seta on each side, occasionally also with a short seta laterally of long seta. Left mandible not truncate, blunted at apex. Dorsal microsculpture highly obliterate, slightly more distinct laterally behind eyes, consisting of a mixture of transverse and almost isodiametric meshes. Antennae in male almost extending to the basal edge of pronotum, with antennomeres 4–8 markedly longer than wide; in female antennae slightly shorter, with shorter antennomeres.

Pronotum: Slightly transverse (PWmax/PL = 1.31–1.36), widest at the end of anterior third, strongly narrowed posteriad (PWmax/PWmin = 1.21–1.29), with one lateral seta inserted slightly before widest point. Sides rounded almost throughout, slightly sinuate just before basal angles (in specimens from Krapa Danda, almost straightly converging in apical third). Apical margin very slightly emarginate or almost straight, bordered only laterally. Apical angles widely rounded, but less so than in the preceding species, not protruded anteriad. Basal margin very broadly rounded or nearly straight medially and slightly oblique laterally, vaguely bordered only at basal angles, approximately as long as apical margin and slightly 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, scarcely widened in apical third. Median line distinct, superficial, ended before apical and basal margins. Basal foveae and lateral depressions absent; occasionally basal foveae present, but poorly delimited, small, somewhat oval and very shallow. Surface sparsely, somewhat coarsely and irregularly punctate along base and in a very narrow area along sides, also vague punctures present at apical margin. Microsculpture highly obliterate, with indistinct meshes on disc, more distinct somewhat isodiametric meshes occasionally visible at apical and basal angles.

Elytra: In lateral and caudal view convex, in dorsal view oval, relatively wide (in males, EL/EW = 1.30–1.36; EL/PL = 2.24–2.39; EW/PWmax = 1.28–1.30; in females, these indices 1.33–1.38, 2.31–2.38, 1.22–1.32, respectively), widest slightly behind middle, with somewhat acute apex. Humeri prominent, angularly rounded at tip, without denticle, at most its very weak traces visible in caudal view. Subapical sinuation very shallow. Sutural angle in both sexes acute and sharp (occasionally slightly blunted) at tip. Basal edge evenly sinuate, forming a very obtuse angle with lateral margin. Striae slightly deepened throughout. Intervals slightly convex throughout, weakly narrowed posteriad. Parascutellar setigerous pore present, large. Parascutellar striole short, shorter than distance from parascutellar pore to suture, with apex free. Interval 3 with a discal setigerous pore at stria 2 behind middle. Marginal umbilicate series widely interrupted at middle, with 6–7 pores in anterior group and 8–9 pores in posterior group. Microsculpture strongly obliterate, indistinct, in some specimens with fine transverse meshes near apex and in external two intervals.

Hindwings: Reduced to tiny scales.

Ventral surface: Prosternum and metasternum finely pubescent. Metepisternum ( Fig. 28 ) slightly wider than long, strongly narrowed posteriad. Apex of last visible (VII) abdominal sternite in both sexes rounded ( Figs 23– 24 ).

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 comparatively weakly widened.

Female genitalia: 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 25–27, 29–31 ) in lateral view arcuate, C-shaped, more strongly bent ventrad just after basal bulb, with almost straight ventral margin in apical two thirds; in dorsal view almost straight, strongly narrowed to apex in distal third. Terminal lamella moderately long, narrowed to apex. Apical capitulum in lateral view ( Figs 25, 29 ) oblique, with acute dorsal flange located less distally than rounded ventral flange; in caudal view ( Figs 26, 30 ) somewhat triangular, narrowly rounded at tip and with sides slightly rounded. Internal sac with a large spiny patch in basal half of median lobe, and with a small medio-ventral group of small spines on left side.

Etymology. The specific name is a Latin adjective meaning “small” and referring to the small body size of the new species.

Comparison. This new species is very similar to T. (B.) holzschuhi and T. (B.) baglungensis sp. n. in many characters including humerus without denticle, metepisternum short, protibia not sulcate dorsally, and median lobe of the aedeagus arcuate, with inclined apical capitulum. In general appearance and reduced dorsal microsculpture, it is particularly similar to the latter species. Trichotichnus (B.) parvulus sp. n. differs from both these species in having smaller body size (4.8–5.4 mm versus 5.4–6.2 mm), mentum and submentum separated by transverse suture medially and fused laterally, pronotum slightly more strongly narrowed basally and with lateral gutters scarcely widened in apical third, elytra with deeper striae and more convex intervals, sutural angle more produced posteriad and sharper at apex, femora not or only slightly infuscate, and aedeagal median lobe with apical capitulum relatively smaller and more strongly oblique; internal sac has a large spiny patch basally and a small media-ventral group of small spines on the left side. For comparison with the sympatric T. (B.) panchhaseensis sp. n. see below under Comparison chapter of the latter species.

Distribution ( Fig. 151 , 3). Mt. Panchhase and Krapa Danda mountain range on southern slope of the Annapurna Himal in western Central Nepal, Kaski District, at altitudes of approximately 1800–2300 m. The species occurs sympatricly with T. (B.) panchhaseensis sp. n. ( Fig. 151 , 7 ).

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.

FIGURES 22 – 31. Trichotichnus (Bottchrus) parvulus sp. n. (22 – 24, 28, paratypes from Mt. Panchhase; 25 – 27, holotype; 29 – 31, paratype from Krapa Danda mountain range). 22, mentum and submentum; 23, apex of last (VII) abdominal sternite, male; 24, same, female; 25, 27, 29, 31, median lobe of aedeagus; 26, 30, terminal lamella and apical capitulum of aedeagus; 28, left metepisternum. 22, 24, 28, ventral view; 25, 29, lateral view; 27, 31, dorsal view; 26, 30, caudal view. Scale bars = 0.25 mm (A: Figs 22 – 25, 27 – 29, 31; B: Figs 26 – 30).

FIGURES 5 – 13. Trichotichnus (Bottchrus) holzschuhi Kirschenhofer, 1992 (5 – 7, paratype; 8 – 13, specimens from Sete). 5, terminal lamella of aedeagus; 6 – 8, 11, median lobe of aedeagus; 9, apical capitulum; 10, left metepisternum; 12, apex of last (VII) abdominal sternite, male; 13, same, female. 5, 7, 8, dorsal view; 6, 11, lateral view; 9, caudal view; 10, 12, 13, ventral view. Scale bars = 0.25 mm (A: Figs 5 – 8, 10 – 13; B: Fig. 9).