Trichotichnus (Bottchrus) cyanescens Ito 1998

Trichotichnus (Bottchrus) cyanescens Ito, 1998

(Figs 94, 115–119, 151, 12)

Trichotichnus (Pseudotrichotichnus) cyanescens Ito, 1998: 281. Type locality: above Num, Khandbari Distr., 1900–2200 m, Nepal.

Material examined. 1 ♂, “E Nepal, Dhankuta, Arun Valley, SE des Makalu, Navagaon – Num, 1900– 700 m, 16.VI.1980, C. Holzschuh leg.”, “ Trichotichnus (Bellogenus) holzschuhi n. sp. mihi, det. Kirschenhofer 91, Paratypus ”, also “Kein Typus ” (cWR); 1 ♀, E Nepal, Arun Valley, Bhotebas – Sakuranti, 1700–2000 m, 6.VI.1968, Lebisch & Probst leg. (cWR); 3 ♂, Nepal, Arun Valley to Makalu, Dhabeli, 27°37'22"N 87°18'06"E ", 2340 m, 16.VI.2013, S. Tamang leg. (cJS, ZIN); 1 ♀, E-Nepal, Arun Valley 3 km S Tashigaon, 27°37'05"N 87°14'58"E, 2000 m 11.V.2014, J. Schmidt leg. (cJS); 1 ♀, Nepal, Arun Valley, Deurali, 27°30'14"N 87°15'40"E, 2100 m, 6.VII.2013, S. Tamang leg. (cJS); 1 ♂, Nepal, Arun Valley, Deurali, 27°30'N 87°16'E, ca. 2100 m, 10.V.2014, J. Schmidt leg. (cJS).

Description. Since the species was described in detail by Ito (1998), only the most distinctive characters are listed.

Habitus: As in fig. 94. Body length 6.6–7.2 mm (6.1–6.7 mm, according to the original description), width 2.8– 3.0 mm.

Proportions: PWmax/PL = 1.32–1.41; EL/EW = 1.33–1.42; EL/PL = 2.31–2.46; EW/PWmax = 1.24–1.32; HWmax/PWmax = 0.66–0.69; HWmin/PWmax = 0.53–0.55; PWmax/PWmin = 1.17–1.23; HWmax/HWmin = 1.25–1.26.

Colour: Dorsum with more or less distinct bluish lustre. Legs yellowish brown, with femora not infuscate.

Head: Eyes markedly convex, oval in lateral view. Genae wide, with few short setae. Mentum and submentum separated by transverse suture medially and fused laterally (as in Fig. 22). Microsculpture on head not evident. Antennae short, not reaching pronotal base.

Pronotum: Sides slightly sinuate in apical third, lateral gutter scarcely widened in apical half. Apical angles slightly protruded, rounded at tip. Basal angles sharp, without denticle at tip. Basal margin slightly oblique laterally. Basal fovea small, shallow or slightly deepened. Pronotal disc punctate basally and latero-basally, without punctures at apical margin. Surface with very fine microsculpture consisting of a mixture of transverse and almost isodiametric meshes.

Elytra: Humeral angle without denticle at apex. Basal edge sinuate laterally, forming a moderately obtuse angle with lateral margin. Sutural angle in general acute, slightly blunted at tip. Striae almost superficial or slightly impressed, intervals flat or slightly convex on disc. Parascutellar striole comparatively short. Marginal umbilicate series widely interrupted at middle, with 6–9 pores in anterior group and 8–10 pores in posterior group. Elytral disc with very fine, strongly obliterate microsculpture, consisting of thin lines.

Hindwings: Reduced to short scales.

Ventral surface: Metepisternum (Fig. 115) about as wide as long, strongly narrowed posteriad. Apex of last (VII) abdominal sternite widely rounded or slightly truncate in male (Fig. 116) and clearly rounded in female.

Legs: Protibia with very thin, somewhat indistinct longitudinal sulcus in basal quarter of dorsal surface. Profemur with five setae on anterio-ventral margin. In male, pro- and mesotarsi very weakly widened.

Male genitalia: Median lobe of aedeagus (Figs 117–119) relatively large, in lateral view clearly S-shaped, with convex ventral margin an apical half, curved ventrad just at apex, forming a hook-shaped apical capitulum; the latter in caudal view elongate oval, blunted at tip (Fig. 118). Terminal lamella in dorsal view very short and narrow, with sides scarcely sinuate preapically. Internal sac has two post-medial groups of very small spines ventrally.

Comparison. This species is very similar to T. (B.) loebli from Darjeeling District, India, in size, habitus and many other characters including femora not infuscate, pronotal lateral gutter slightly widened anteriad, humerus without denticle at tip, protibia very finely, indistinctly sulcate on dorsal side, elytra with fine microsculpture, and S-shaped aedeagal median lobe with small spines in the internal sac post-medially. Based on the original description (Ito 1998), T. (B.) loebli differs distinctly in having mentum and submentum completely separated by suture, pronotal basal angles angularly rounded at tip, metepisterna wider, slightly wider than long, and median lobe less strongly curved dorsad in apical portion, supplied with a big transverse apical capitulum having dorsal and ventral flanges approximately equally protruded. For comparison with T. manasluensis sp. n., see under the latter species.

Distribution (Fig. 151, 12). The distribution of this species seems to be restricted to slopes of the middle Arun Valley, Khandbari District, East Nepal, at altitudes of 1700–2540 m.

Remarks. The species was described based on 17 specimens: 11 (including the holotype) from East Nepal and six from Central Nepal. The type series should be re-examined since, according to our data, T. (B.) cyanescens occurs only along slopes of the Arun Valley in East Nepal. The specimens mentioned as paratypes from Central Nepal, apparently belong to other taxa.