Trichotichnus (Bottchrus) pusillus, 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 : 325-328

Trichotichnus (Bottchrus) pusillus sp. n.

( Figs 67–68 , 71–79 , 151 , 9 )

Type material. Holotype: ♂, “ NEPAL Manaslu Mts. 2003, 22.IV., Dudh Pokhari Lekh, below Helam Pokhari, 2000 m, leg. J. Schmidt ” (cJS).

Paratypes: 21 ♂, 8 ♀, same data as holotype (cJS, ZIN); 1 ♂, 1 ♀, Manaslu Mts. , Dudh Pokhari Lekh , upp. Jorney vill., 2100–2600 m, 15.IX.1995, J. Schmidt leg. (cJS); 11 ♂, 15 ♀, Manaslu Mts. , Dudh Pokhari Lekh , upper Phulinggiri Madi , 2100–2500 m, 19–21.IV.2003, J. Schmidt leg. (cJS); 3 ♀, Manaslu Mts. , Dudh Pokhari Lekh , Dordi Khola Valley , 2000–2300 m, 14–15.IV.2003, J. Schmidt leg. (cJS); 11 ♂, 8 ♀, Manaslu Mts , Bara Pokhari Lekh , Chhandi Khola Vall., 2000–2200 m, 11–12.IV.2003, J. Schmidt leg. (cJS); 4 ♂, 7 ♀, Manaslu Mts, S of Bara Pokhari , 2000 m, 8.IV.2003, J. Schmidt leg. (cJS); 3 ♂, 3 ♀, Manaslu Mts, S of Bara Pokhari , 2000 m, 1.IV.1999, Lau & J. Schmidt leg. (cJS, ZIN); 1 ♂, 1 ♀, Manaslu Mts , Bara Pokhari Lekh , upp. Taksar vill., 2000– 2100 m, 1+ 11.IV.1999 (cJS); 6 ♂, 4 ♀, same as preceding but 7.IV.2003, J. Schmidt leg. (cJS); 42 ♂, 13 ♀, Manaslu Mts. , S Bara Pokhari, ca. 28°15’N 84°25’E, 2000–2100 m, 29.IV.2005 (cJS, ZIN); 1 ♀, C-Nepal, Manaslu massif, Barapokhari Lekh, 23 km NE Besisahar vill., 2000–3000 m , 28°21'N, 84°33'E, VII.2010, Santos leg. (cWR).

Additional material. 1 ♂, 1 ♀, Nepal, Annapurna , Telbrung Danda, 2000 m, 15.VI.1997, J. Schmidt leg. (cJS).

Description. Habitus as in figs 67–68. Body length 5.3–6.0 mm, width 2.4–3.6 mm.

Colour: Body piceous, shiny on dorsum, with light, but distinct bluish or greenish tinge on elytra and often also on pronotum; labrum, in most specimens also base of mandibles, lateral gutters of pronotum and elytra reddish brown; palpi, antennae and legs brownish yellow, occasionally femora slightly infuscate.

Head: Comparatively large, with wide neck (in males, HWmax/PWmax = 0.68–0.71, HWmin/PWmax = 0.54– 0.60; in females, these indices 0.69–0.73 and 0.57–0.60, respectively). Eyes moderately convex (in males, HWmax/HWmin = 1.21–1.30, and in females, 1.18–1.23), in lateral view somewhat wide oval. Tempora about one third as long as eye, slightly convex, sloped somewhat abruptly to neck. Genae wide, about 1.75 as wide as width of antennomere 1, with few short setae. Lateral margin of head between antenna and eye, like in all the preceding species, slightly protruded laterally, forming an obtuse angle near eyes, distinctly bordered. Area between supraorbital furrow and upper margin of eye approximately as wide as or slightly shorter than width of antennomere 3 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 slightly or moderately concave anteriorly. Clypeus slightly emarginate along apical margin, slightly convex basally, flatly sloped to apex, with one setigerous pore at each apical angle. Frons and vertex convex. Mentum and submentum completely fused, submentum on each side with one long seta and additionally with one short seta laterally of long seta. Left mandible not truncate, slightly blunted at apex. Dorsal microsculpture visible 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: Moderately wide (PWmax/PL = 1.33–1.44), widest at the end of anterior third, slightly to moderately narrowed posteriad (PWmax/PWmin = 1.14–1.28), with one lateral seta inserted slightly before widest point. Sides rounded anteriorly, almost straight or more widely rounded in basal third, in some specimens slightly sinuate in short distance just before basal angles. Apical margin slightly emarginate, finely bordered laterally. Apical angles slightly, but clearly protruded ahead, comparatively narrowly rounded at tip. Basal margin nearly straight or slightly oblique laterally, vaguely bordered laterally, markedly longer than apical margin and slightly shorter than base of elytra between humeral angles. Basal angles more or less obtuse, more or less clearly denticulate at tip, often with an acute apex laterally projected. Pronotal disc moderately convex, strongly sloped to apical angles and moderately so to basal ones, not depressed basally, but slightly flattened in comparatively wide latero-basal area. Lateral gutter very narrow, slightly widened in apical third. Median line very fine, not deepened, rather long, ended slightly before apical and basal margins. Basal foveae small, oval or somewhat elongate, very shallow, usually poorly delimited. Surface sparsely, irregularly punctate in latero-basal areas before lateral seta, with few indistinct punctures or almost impunctate at anterior margin and in middle basal portion. Microsculpture very obliterate, recognizable usually only along sides, consisting of very fine transverse meshes.

Elytra: In lateral and caudal view convex, in dorsal view oval, moderately wide (in males, EL/EW = 1.31–1.37; EL/PL = 2.20–2.39; EW/PWmax = 1.24–1.29; in females, these indices 1.28–1.38, 2.19–2.44, 1.21–1.30, respectively), widest just behind middle, with somewhat acute apex. Humeri prominent, angularly rounded at tip, with a small, but distinct acute denticle visible from behind. Subapical sinuation very shallow. Sutural angle acutangular in general, sharp or blunted at tip. Basal edge evenly curved ahead laterally, forming a sharp, obtuse angle with lateral margin. Elytral striae thin, usually slightly impressed; intervals flat or subconvex throughout, weakly narrowed posteriad. 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. Interval 3 with a distinct discal setigerous pore at stria 2 behind middle. In many specimens elytra near apex with a short additional stria 9 separated from lateral gutter by distinct convexity. Marginal umbilicate series widely interrupted at middle, with 7– 8 pores in anterior group and 8–10 pores in posterior group. Microsculpture strongly reduced, very fine transverse meshes evident in very narrow areas along margins.

Hindwings: Reduced to tiny scales.

Ventral surface: Prosternum and metasternum finely pubescent. Metepisternum ( Fig. 71 ) slightly wider than long, narrowed posteriad. Apex of last visible (VII) abdominal sternite in both sexes rounded at apex, in female ( Fig 79 ) more angularly than in male ( Fig 78 ).

Legs: Protibia very finely longitudinally sulcate on dorsal side in its basal two-third. Profemur usually with four, more rarely with five or three setae on anterio-ventral margin. Tarsi short, metatarsus noticeably shorter than HWmin, with metatarsomeres (particularly 2–4) moderately widened posteriad, metatarsomere 1 approximately as long as metatarsomeres 2+3. Tarsomere 5 with two, occasionally three pairs of ventro-lateral setae. In male, pro- and mesotarsi moderately strongly widened.

Female genitalia: Laterotergite (hemisternite) symmetrical, with two 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 72–77 ) in lateral view evenly arcuate, C-shaped, with ventral margin more or less roundly emarginate throughout, with apical third strongly bent ventrad; in dorsal view median lobe almost straight, markedly narrowed to apex in distal half. Terminal lamella in dorsal view moderately short, markedly narrowed posteriad and more or less clearly sinuate at sides just at apex. Apical capitulum in lateral view ( Figs 72–73, 75 ) almost transverse, more strongly prominent dorsally than ventrally, in caudal view ( Figs 74, 76 ) discoidal, rounded at tip. Internal sac without spines and distinct spiny patches.

Etymology. The specific name is derived from the Latin adjective meaning “tiny” and refers to the small body size of the beetle.

Comparison. In size and general habitus, T. (B.) pusillus sp. n. is very similar to T. (B.) baglungensis sp. n. and slightly more robust than T. (B.) panchhaseensis sp. n. and T. (B.) siklesensis sp. n. Trichotichnus (B.) pusillus sp. n. is also characterized by metepisternum slightly wider than long ( Fig. 71 ), mentum and submentum completely fused, pronotal lateral gutter slightly widened in apical third, humerus with a distinct acute denticle at apex, protibia very finely longitudinally sulcate on dorsal side, and microsculpture indistinct on pronotal and elytral discs. It is distinctly distinguished from all other species of Bottchrus of the Himalayan region by the peculiar male genitalia with C-shaped aedeagal median lobe ( Figs 72–77 ) which is bent ventrad approximately equally basally and apically; its terminal lamella is moderately long, slightly widened apically and supplied with a small transverse apical capitulum; the latter is discoidal in caudal view ( Figs 74–76 ). Trichotichnus (B.) manasluensis sp. n., occurring sympatricly with T. (B.) pusillus sp. n., is easily distinguished from the latter by having larger size (5.9–6.3 mm), humerus without denticle, last (VII) abdominal sternite in female somewhat angulate at apex ( Fig. 111 ) and median lobe of the aedeagus in lateral view almost straight, only slightly S-shaped ( Figs 112, 114 ).

Distribution ( Fig. 151 , 9 ). Dudh Pokhari Lekh and Bara Pokhari Lekh mountain ranges on the southern slopes of Manaslu Himal, western Central Nepal, Lamjung District, at altitudes of 2000–2600 m. Also found in the Telbrung Danda mountain range on southern slope of Lamjung Himal (south-eastern slope of Annapurna Himal). In the Manaslu Himal, T. (B.) pusillus sp. n. occurs sympatricly with T. (B.) manasluensis sp. n. ( Fig. 152 , 3).

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.

FIGURE 152. Distribution of the Himalayan species of Trichotichnus subgenus Bottchrus. 1, T. gupchiensis sp. n.; 2, T. brancuccii sp. n.; 3, T. manasluensis sp. n.; 4, T. loebli Ito, 1998; 5, T. sikkimensis sp. n.; 6, T. hingstoni Andrewes, 1930.

FIGURES 67 – 70. Himalayan species of Trichotichnus subgenus Bottchrus, photographs of habitus. 67, T. pusillus sp. n., paratype, male, from the Bara Pokhari Lekh mountain range; 68, T. pusillus sp. n., paratype, male, from the Dudh Pokhari Lekh mountain range; 69, T. ganeshensis sp. n., paratype, male; 70, T. minutus sp. n., paratype, male.

FIGURES 71 – 79. Trichotichnus (Bottchrus) pusillus sp. n. (71, 78, 79, paratypes from Dudh Pokhari Lekh; 72, specimen from Annapurna; 73, 74, paratype from Bara Pokhari Lekh; 75 – 77, holotype). 71, left metepisternum; 72 – 73, 75, 77, median lobe of aedeagus; 74, 76, apical capitulum; 78, apex of last (VII) abdominal sternite, male; 79, same, female. 71, 78 – 79, ventral view; 72 – 73, 75, lateral view; 74, 76, caudal view; 77, dorsal view. Scale bars = 0.25 mm (A: Figs 71 – 73, 75, 77 – 79; B: Figs 74, 76).

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).

FIGURES 109 – 114. Trichotichnus (Bottchrus) manasluensis sp. n. (109, 111, paratypes; 112 – 114, holotype). 109, left metepisternum; 110, apex of last (VII) abdominal sternite, male; 111, same, female; 112, 114, median lobe of aedeagus; 113, apical capitulum. 109 – 111, ventral view; 112, lateral view; 113, caudal view; 114, dorsal view. Scale bars = 0.25 mm (A: Figs 109 – 112, 114; B: Fig. 113).