Trichotichnus (Bottchrus) schawalleri, 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 : 315-318

Trichotichnus (Bottchrus) schawalleri sp. n.

( Figs 38 , 42–46 , 151 , 5 )

Type material. Holotype: ♂, “539 NEPAL: Bhojpur Distr. Dilkharka 2100 m, 26.V.1997 leg. W. SCHAWALLER”, “Mus. Stuttg” ( SMNS).

Paratype: Nepal: 1 ♂, “536 NEPAL: Bhojpur Distr. Valley NW Phedi 1900 m, 25.V.1997 leg. W. SCHAWALLER”, “Mus. Stuttg” (cJS).

Description (male). Habitus as in Fig. 38 . Body length in holotype 5.8, in paratype 6.1 mm, width 2.7 and 2.8 mm, respectively.

Colour: Body piceous, shiny on dorsum, with light bluish or blue greenish tinge; labrum, very narrow margins of pronotum and apical portion of elytral margins as well as of elytral epipleurae slightly paler; palpi, antennae and legs brownish yellow.

Head: Comparatively large, slightly smaller than in T. (B.) bubsaensis sp. n., with wide neck (HWmax/PWmax = 0.67, HWmin/PWmax = 0.55–0.57). Eyes rather convex (HWmax/HWmin = 1.17–1.22), but slightly less than in T. (B.) bubsaensis sp. n., in lateral view elongate oval. Tempora about half as long as eye, slightly convex, somewhat abruptly sloped to neck. Genae almost twice as wide as 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, very finely 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 slightly concave anteriorly. Clypeus very slightly emarginate along anterior margin, moderately convex basally, flatly sloped to apex, with a comparatively large setigerous pore at each anterior corner. Frons and vertex convex. Mentum and submentum completely fused, submentum with one long seta and a shorter one laterally of the long seta on each side. Left mandible not truncate, slightly blunted at apex. Dorsal microsculpture consisting of obliterate weakly transverse meshes. Antennae (in male) almost extending to the basal edge of pronotum, with antennomeres 4–8 markedly longer than wide.

Pronotum: Comparatively wide (PWmax/PL = 1.41), widest at the end of anterior third, moderately narrowed posteriad (PWmax/PWmin = 1.18–1.19), with one lateral seta inserted slightly before the widest point. Sides rounded almost throughout, slightly sinuate just before basal angles. Apical margin very slightly emarginate, bordered only laterally. Apical angles very slightly prominent anteriad, widely rounded at tip. Basal margin nearly straight, only slightly roundly oblique laterally, vaguely bordered in lateral third, slightly longer than apical margin and slightly shorter than base of elytra between humeral angles. Basal angles slightly more than 90, each with a sharp, subdenticulate apex slightly protruded laterad. Pronotal disc moderately convex, strongly sloped to apical angles and moderately so to basal ones, not depressed basally although latero-basal areas slightly flattened. Lateral gutter very narrow, very hardly widened in apical third. Median line interrupted, very fine, superficial, ended markedly before apical and basal margins. Lateral depressions absent; basal foveae small, somewhat elongate and very shallow. Surface sparsely, somewhat finely and irregularly punctate mainly in latero-basal areas, with middle basal portion impunctate, punctation at apical margin absent. Microsculpture present throughout, distinct; meshes mostly transverse, between apical margin and anterior transverse impression more or less isodiametric.

Elytra: In lateral and caudal view convex, in dorsal view oval, relatively wide (in male, EL/EW = 1.30–1.31; EL/PL = 2.32–2.45; EW/PWmax = 1.27–1.32), widest approximately at middle, with somewhat acute apex. Humeri prominent, rather widely angularly rounded at tip, without denticle. Subapical sinuation shallow. Sutural angle acute and somewhat sharp at tip. Basal edge markedly sinuate laterally, forming distinct obtuse angle with lateral margin. Striae fine, almost superficial along entire length. Intervals somewhat flat throughout, weakly narrowed posteriad. Parascutellar setigerous pore present, large. Parascutellar striole rudimentary, almost absent. Interval 3 with a very small discal setigerous pore at stria 2 behind middle. Marginal umbilicate series widely interrupted at middle, with 6–8 pores in anterior group and 8–9 pores in posterior group. Microsculpture fine, poorly recognizable, consisting of thin transverse lines.

Hindwings: Reduced to tiny scales.

Ventral surface: Prosternum and metasternum finely pubescent. Metepisternum ( Fig. 42 ) markedly wider than long, strongly narrowed posteriad. Apex of last visible (VII) abdominal sternite (in male) subtruncate and slightly concave just at tip ( Fig. 43 ).

Legs: Protibia without longitudinal sulcus on upper surface. Profemur with four setae on anterio-ventral margin. Tarsi short, similar to those in T. (B.) parvulus sp. n., metatarsus noticeably shorter than HWmin, with metatarsomeres (particularly 2–4) 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 moderately widened.

Male genitalia: Median lobe of aedeagus ( Figs 44–46 ) in lateral view rather evenly arcuate, C-shaped, with almost straight middle portion of ventral margin and with apical third curved ventrad; in dorsal view almost straight, narrowed to apex in distal third. Terminal lamella moderately short, narrowed to apex. Apical capitulum in lateral view ( Fig. 44 ) very oblique, poorly delimited, almost not protruded ventrad and dorsad, narrowly rounded at tip; in caudal view ( Fig. 45 ) triangular, somewhat horseshoe-shaped, rather acute, only slightly blunted at tip. Internal sac without distinct spiny patches and other sclerotic elements.

Etymology. This new species is named after the famous coleopterologist Wolfgang Schawaller (Stuttgart), who collected the type specimens.

Comparison. Trichotichnus (B.) schawalleri sp. n. is very similar to T. (B.) holzschuhi and all the other preceding species in habitus and in having metepisternum short, protibia not sulcate dorsally, and aedeagal median lobe arcuate, with inclined apical capitulum, but easily recognized from them in the combination of the following characters: pronotum rather wide, moderately narrowed basad; dorsal microsculpture present throughout on head, pronotum and elytra; parascutellar striole rudimentary, almost absent; apex of last visible (VII) abdominal sternite in male ( Fig. 43 ) subtruncate and slightly concave just at tip [in this character, T. (B.) schawalleri sp. n. is similar only to T. (B.) hingstoni ]; median lobe ( Figs 44–46 ) with shorter terminal lamella and very oblique, horseshoeshaped apical capitulum, which is poorly separated from the terminal lamella in lateral view and almost triangular [as in T. (B.) hingstoni ], with rather acute, only slightly blunted tip, in caudal view ( Fig. 45 ); and internal sac with characteristic pattern of spiny folders in the middle portion of the median lobe. Trichotichnus (B.) cyanescens , probably occurring sympatricly with T. (B.) schawalleri sp. n., is somewhat similar to the new species in habitus, but easily distinguished by having larger size (6.1–6.9 mm), metepisternum ( Fig. 115 ) slightly more elongate, mentum and submentum fused only laterally, apex of last (VII) abdominal sternite ( Fig. 116 ) in male rounded, and median lobe of aedeagus ( Figs 117–119 ) S-shaped, hooked at apex. Trichotichnus (B.) hingstoni , also occurring sympatricly with this new species, is easily distinguished from in having larger size (6.8–7.7 mm), genae glabrous, metepisterna ( Fig. 137 ) markedly longer, pronotum never sinuate basally and with narrow, apically not widened lateral gutter, protibia longitudinally sulcate on dorsal side, and apical capitulum of the aedeagal median lobe ( Figs 135–136 , 140 ) more strongly prominent dorsally and ventrally.

Distribution ( Fig. 151 , 5 ). Up to today only known from the western slope of the middle Arun River Valley towards Salpa pass, Bhojpur District, East Nepal, at altitudes of approximately 1900–2100 m. This species seems to occur sympatricly with T. (B.) hingstoni ( Fig. 152 , 6 ). Another species, T. (B.) cyanescens , was found in the Arun River Valley slightly further north ( Fig. 151 , 12 ).

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 38 – 41. Himalayan species of Trichotichnus subgenus Bottchrus, photographs of habitus. 38, T. schawalleri sp. n., holotype; 39, T. obliquebasalis sp. n., paratype, male; 40, T. siklesensis sp. n., paratype, male; 41, T. panchhaseensis sp. n., paratype, male.

FIGURES 42 – 46. Trichotichnus (Bottchrus) schawalleri sp. n. (42 – 43, paratype; 44 – 46, holotype). 42, left metepisternum; 43, apex of last (VII) abdominal sternite, male; 44, 46, median lobe of aedeagus; 45, apical capitulum. 42 – 43, ventral view; 44, lateral view; 45, caudal view; 46, dorsal view. Scale bars = 0.25 mm (A: Figs 42 – 44, 46; B: Fig. 45).

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 115 – 119. Trichotichnus (Bottchrus) cyanescens Ito, 1998 (specimen from Dhabeli). 115, left metepisternum; 116, apex of last (VII) abdominal sternite, male; 117, 119, median lobe of aedeagus; 118, apical capitulum. 115 – 116, ventral view; 117, lateral view; 118, caudal view; 119, dorsal view. Scale bars = 0.25 mm (A: Figs 115 – 117, 119; B: Fig. 118).

FIGURES 137 – 145. Trichotichnus (Bottchrus) hingstoni Andrewes, 1930 (137 – 139, Kechu Pheri Lake, W-Sikkim; 140 – 143, Maney Bhanjyang, Darjeeling, 144, above Yamputhin, Nepal; 145, Ting Sang La, Nepal). 137, left metepisternum; 138, apex of last (VII) abdominal sternite, male; 139, same, female; 140, 142, median lobe of aedeagus; 141, apical capitulum; 143 – 145, middle portion of median lobe. 137 – 139, ventral view; 140, left lateral view; 141, caudal view; 142, dorsal view; 143 – 145, right lateral view. Scale bars = 0.25 mm (A: Figs 137 – 140, 142 – 145; B: Fig. 141).

FIGURES 135 – 136. Trichotichnus (Bottchrus) hingstoni Andrewes, 1930, median lobe of aedeagus, lateral view (135, lectotype; 136, holotype of T. curvatus Ito, 1996). Scale bar = 1.0 mm.