Trichotichnus (Bottchrus) brancuccii, 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 : 335-337

Trichotichnus (Bottchrus) brancuccii sp. n.

( Figs 92 , 103–108 , 152 , 2)

Type material. Holotype: ♂, “ Nepal Bagmati Sindhupalchok, Manegero [= Melamchigaon?] 2500 m 13.VI. 89 M. Brancucci”, “NATURHIST. MUSEUM BASEL ” ( NHMB).

Paratype: 1 ♂, “ Nepal Bagmati Sindhupalchok, Sarmatang-Gangjwal 2500 m 5.VI.89 M. Brancucci ”, “NATURHIST. MUSEUM BASEL ” (cJS).

Description (male). Habitus as in Fig. 92 . In holotype, body length 6.5 mm, width 2.9 mm; in paratype, 5.9 and 2.9 mm, respectively.

Colour: Body piceous black, shiny, with bluish tinge, on dorsum; labrum, pronotum and elytra within lateral gutters paler, reddish brown; palpi, antennae and legs yellowish brown, with femora and trochanters distinctly infuscate.

Head: Large, with wide neck (in holotype, HWmax/PWmax = 0.70, HWmin/PWmax = 0.57; in paratype, 0.74 and 0.59, respectively). Eyes markedly convex (in holotype, HWmax/HWmin = 1.23, and in paratype, 1.25), in lateral view comparatively narrow, elongate semi-oval. Tempora comparatively long, about half as long as eye, slightly convex, somewhat abrupt to neck. Genae wide, about 1.5 times as wide as width of antennomere 1, with few short setae. Lateral margin of head between antenna and eye only hardly protruded laterally, forming a small obtuse angle near eyes, distinctly, but rather finely bordered. Area between supraorbital furrow and upper margin of eye approximately as wide as or slightly narrower than 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 slightly emarginate along anterior margin, moderately convex basally, flatly sloped to apex, with one comparatively large setigerous pore at each apical angle. Frons and vertex convex. Mentum and submentum separated by transverse suture medially and fused laterally (as in Fig. 22 ). Submentum on each side with one long seta. Left mandible not truncate, blunted at apex. Dorsal microsculpture strongly obliterate, more or less distinct transverse and almost isodiametric meshes visible only laterally behind eyes. Antennae (in males) extending to the basal edge of pronotum, with antennomeres 4–8 markedly longer than wide.

Pronotum: Slightly transverse (PWmax/PL = 1.37–1.39), widest slightly before anterior third, comparatively strongly narrowed posteriad (PWmax/PWmin = 1.27–1.31), with one lateral seta inserted slightly before widest point. Sides rounded anteriorly, very broadly so in basal third and slightly sinuate in very short distance just in front of basal angles. Apical margin more markedly arcuately emarginate than in T. (B.) gupchiensis sp. n., bordered throughout, and apical angles more prominent anteriad and more narrowly rounded at tip. Basal margin almost straight or (in paratype) slightly concave in middle portion, vaguely bordered laterally, slightly longer than apical margin and slightly shorter than base of elytra between humeral angles. Basal angles obtuse, subdenticulate (in holotype) or denticulate (in paratype) at apex. Pronotal disc convex, strongly sloped to apical angles and moderately so to basal ones, not depressed basally, but slightly flattened in narrow area latero-basally. Lateral gutter very narrow in posterior half and markedly widened in anterior half. Median line very fine, superficial, ended markedly before apical and basal margins. Basal foveae distinct, wide and shallow. Surface comparatively coarsely and irregularly punctate along base and in latero-basal area behind lateral seta, with finer obliterate punctures in medio-basal area, and at most with few vague punctures at apical margin. Pronotal surface without evident microsculpture on disc.

Elytra: In lateral and caudal view convex, in dorsal view oval, elongate, moderately wide (in holotype, EL/EW = 1.35; EL/PL = 2.33; EW/PWmax = 1.24; in paratype, these indices 1.39, 2.41, 1.26, respectively), widest at middle, with somewhat acute apex. Humeri prominent, angularly rounded at tip, without denticle. Subapical sinuation very shallow. Sutural angle somewhat acutangular, with a small acute tooth projected posteriad. Basal edge slightly sinuate, forming with lateral margin a slightly obtuser angle than in T. (B.) gupchiensis sp. n. Striae superficial, finely crenulate anteriorly. Parascutellar setigerous pore large. Parascutellar striole slightly longer than distance from parascutellar pore to suture, with apex free or connected with stria 1. Intervals flat. Interval 3 with a discal setigerous pore at stria 2 behind middle. Elytra near apex with a short additional stria 9 separated from lateral gutter by a distinct convexity. Marginal umbilicate series widely interrupted at middle, with 7–8 pores in anterior group and 8–10 pores in posterior group. Microsculpture evident on two lateral intervals, consisting of fine slightly transverse meshes.

Hindwings: Reduced to tiny scales.

Ventral surface: Prosternum and metasternum finely pubescent. Metepisternum ( Fig. 103 ) markedly wider than long, moderately narrowed posteriad. Apex of last visible (VII) abdominal sternite (in male) somewhat angularly rounded ( Figs 104–105 ).

Legs: Protibia not sulcate. Profemur with five to six 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 very moderately widened.

Male genitalia: Median lobe of aedeagus ( Figs 106–108 ) in lateral view arcuate, with ventral margin evenly convex in apical half and with comparatively long and narrow terminal lamella bent dorsad; ventral margin of terminal lamella convex; in dorsal view median lobe almost straight, moderately narrowed to apex in distal half. Terminal lamella in dorsal view much wider than in T. (B.) gupchiensis sp. n., markedly sinuate at sides. Apical capitulum in lateral view hook-shaped, not prominent dorsally ( Fig. 106 ), in caudal view triangular, with acute tip ( Fig. 107 ). Internal sac without large spines, with wide spiny patch basally.

Etymology. This new species is named in honour of the late Dr. Michel Brancucci, famous coleopterologist and curator of the Natural History Museum, Basel, who collected the type specimens.

Comparison. This new species is similar to T. (B.) gupchiensis sp. n. in general habitus, short metepisterna, highly reduced dorsal microsculpture, not sulcate tibia and comparatively long terminal lamella of aedeagus, but differs markedly in having larger body size (5.9–6.5 mm versus 5.2–5.9 mm), pronotum more notably narrowed to base, with distinctly widened apically lateral gutter and slightly concave basal margin, mentum and submentum separated by transverse fissure medially and fused laterally [similar in this character to T. (B.) parvulus sp. n. and T. (B.) cyanescens ], humerus without denticle, elytral sutural angle narrowly rounded at tip, and last (VII) abdominal sternite in male angularly rounded at apex [in T. (B.) gupchiensis sp. n., more widely rounded]. In addition, T. (B.) brancuccii sp. n. is well distinguished from T. (B.) gupchiensis sp. n. as well as from all other species of that subgenus in the following characters of the male genitalia ( Figs 106–108 ): aedeagal median lobe in lateral view Sshaped, with apical third curved dorsad, evenly convex along ventral margin and hooked at apex; in dorsal view, terminal lamella wider and noticeably widened apically, apical capitulum in caudal view wide, triangular.

Distribution ( Fig. 152 , 2). Up to today only known from the southern slope of the Helambu mountain range (source area of Indrawati Nadi River), Sindhupalchok District, Central Nepal, at an altitude of approximately 2500 m. This species seems to be a geographical vicariant of T. (B.) gupchiensis sp. n. which is known from the southeastern slope of the Manaslu Himal ( Fig. 152 , 1).

Figures

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 91 – 94. Himalayan species of Trichotichnus subgenus Bottchrus, photographs of habitus. 91, T. gupchiensis sp. n., paratype, male. 92, T. brancuccii sp. n., paratype, male. 93, T. manasluensis sp. n., paratype, male. 94, T. cyanescens Ito, 1998, male from Dhabeli.

FIGURES 103 – 108. Trichotichnus (Bottchrus) brancuccii sp. n. (103, 105, paratype; 104, 106 – 108, holotype). 103, left metepisternum; 104, 105, apex of last (VII) abdominal sternite, males; 106, 108, median lobe of aedeagus; 107, apical capitulum. 103 – 105, ventral view; 106, lateral view; 107, caudal view; 108, dorsal view. Scale bars = 0.25 mm (A: Figs 103 – 106, 108; B: Fig. 107).

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).