Trechus colobus Schmidt & Faille 2018, sp. nov.
Creators: name: Schmidt, Joachim
name: Faille, Arnaud
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Carabidae
Trechus
Trechus colobus

description: Trechus colobus sp. nov.
urn:lsid:zoobank.org:act: 2A138A6D-177D-46B5-8AE0-1F7CD050B9E6
Figs 70, 74, 78, 120–121
Diagnosis
Externally, this new species is very similar to T. bastianinii, but its body length is average smaller (3.8–4.5 mm instead of 4.5–5.0 mm in T. bastianinii). However, it differs markedly by the shape of the aedeagal median lobe and the structures of endophallus: In lateral view, the median lobe is more markedly bent behind basal bulb and much more convex in middle; in dorsal view, the median lobe is awl-like, narrowed towards apex and not widened as in T. bastianinii; the markedly sclerotized sheetlike folding structure of endophallus below the copulatory piece is unique amongst Trechus of the study area.
Etymology
Named after the famous monkey Guereza Colobus (Colobus guereza Rüppell, 1835) which occurs in the forests along slopes of the western Bale Mts together with this new species of Trechus.
Material examined
Holotype
ETHIOPIA: ³, Oromia, western Bale Mts, above Dodola, alt. 3400–3700 m, 06°51′ N, 39°14′ E, Dec. 2006 (CSCHM, registration number ZSM _COL_2018_015).
Paratypes
ETHIOPIA: 39 specimens (³³, ♀♀), same data as for holotype (CAF, CSCHM); 7 ³³, 2 ♀♀, same data as for preceding, alt. 2700–2850 m, 06°53′49″ N, 39°11′32″ E, Dec. 2006 (CAF, CSCHM); 66 specimens (³³, ♀♀), Bale Mts, South of Adaba, alt. 3170 m, 06°49′31″ N, 39°25′37″ E, Feb. 2007 (NHMUK, CAF, MNHN, CSCHM); 7 ³³, 7 ♀♀, near pass south of Adaba, alt. 3250 m, 06°46′33″ N, 39°24′58″ E, 22 Feb. 2017 (CAF, CSCHM).
Description
BODY LENGTH. 3.8–4.5 mm (Ø = 4.26 mm, n = 20).
PROPORTIONS (n = 10). PW/HW = 1.38–1.45 (Ø = 1.42); PW/PL = 1.38–1.45 (Ø = 1.41); PW/PBW = 1.24–1.30 (Ø = 1.27); EW/PW = 1.42–1.51 (Ø = 1.47); EL/EW = 1.32–1.42 (Ø = 1.37).
COLOUR. Head, pronotum and elytra blackish brown, elytra markedly shiny, iridescent. Clypeus and elytral side margin reddish brown lightened. Lateral margin of labrum, palpi, antennal base, elytral apex, and legs light brown; antennae distally darkened beginning from third antennomere.
MICROSCULPTURE. Same in males and females. Head with rather large, deeply engraved, almost isodiametric meshes on disc and supraorbital area, and smaller, slightly engraved meshes on clypeus. Pronotum with moderately large, slightly transverse meshes. Elytra with very slightly engraved very narrow transverse meshes.
HEAD. Moderately robust. Mandibles moderately short. Labrum with apical margin widely emarginated. Eyes large, convexly protruded. Tempora moderately short, convex, markedly wrinkled to the neck, 0.35–0.45 times as long as eyes, smooth. Frons and supraorbital area strongly convex, with supraorbital furrows almost uniformly bent on disc, deep throughout. Length of antennae average for Trechus, proportions of the first four antennomeres as follows: 1/0.8/0.9/0.8.
PROTHORAX. Pronotum moderately large and transverse, broadest portion slightly before middle, base slightly wider than apical margin. Disc moderately convex. Anterior margin slightly concave with anterior angles slightly protruded, rounded. Sides almost evenly rounded throughout, sometimes straight before laterobasal angles; latter small, rectangular or slightly obtuse, not or very slightly protruded laterally. Marginal gutter narrow in anterior 8 /10, distinctly widened near laterobasal angles. Base straight in middle, very slightly bent anteriorly near laterobasal angles. Median longitudinal impression very fine, not deepened near base, disappearing at apex; anterior transverse impression indistinct, smooth; posterior transverse impression and laterobasal foveae very shallow, smooth. Pronotum with laterobasal setae present.
PTEROTHORAX. Elytra convex on disc, not or very slightly flattened if viewed from behind, in dorsal view broad oval, broadest in mid-length, with shoulders broadly rounded; apex suggestively pointed. Striae impunctate or suggestively punctate, parascutellar stria moderately short, deep, striae 1–2 (3) deeply impressed, 4 and 5 very fine, 6–7 usually absent, 8 deeply impressed from level of the middle group of the marginal umbilicate pores towards apex. Internal 3–4 intervals slightly convex. Recurrent preapical stria deep, short, slightly curved in front, directed to the seventh stria. Third stria with two setiferous dorsal pores, the anterior one near the end of the anterior elytral quarter, the posterior one in middle, and with preapical seta, which is situated at the apical anastomosis of second and third striae, almost as close to the elytral apex as to the suture. Number and positions of the setae of the marginal umbilicate series as in Trechus s. str.
LEGS. Moderately short and comparatively thin; protibia slightly dilated towards apex, almost straight, distinctly grooved on external surface. Two basal protarsomeres of male dilated.
MALE GENITALIA. EL/AL = 2.31–2.65 (Ø = 2.42, n = 8). Aedeagal median lobe rather slender, its ventral margin in lateral view sinusoidal, markedly bent behind basal bulb and convex in middle; apical lamella rather long, in dorsal view awl-shaped, in lateral view with apex formed as a small hook bent upward; basal bulb and sagittal aileron average. Endophallic copulatory piece rather small, spine-like, its distal portion surrounded from a small, markedly sclerotized, sheet-like folding structure.
Distribution
Endemic to the western portion of the Bale Mts, here found along slopes south of the cities Dodola and Adaba. The species was collected at altitudes of 2700–3500 m.
description: Published as part of Schmidt, Joachim & Faille, Arnaud, 2018, Revision of Trechus Clairville, 1806 of the Bale Mountains and adjacent volcanos, Ethiopia (Coleoptera, Carabidae, Trechini), pp. 1-82 in European Journal of Taxonomy 446 on pages 41-43, DOI: 10.5852/ejt.2018.446, http://zenodo.org/record/3829902