Trechus tragelaphus 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 tragelaphus

description: Trechus tragelaphus sp. nov.
urn:lsid:zoobank.org:act: 9BD6D87E-FAF4-4B63-B158-E98DF905C11C
Figs 104, 108, 112, 135
Diagnosis
Due to the markedly rounded pronotal basal angles, this new species is similar to T. baleensis and T. rotundicollis, but its body length is distinctly smaller (4.5–4.6 mm instead of> 5.1 mm) and the endophallus much less extensively sclerotized. Similar species from the Bale Mts are also T. batuensis and T. haggei sp. nov., however, these species are easy to distinguish due to the large and deeply engraved meshes of elytral microsculpture. Species related to T. ericalis differ, inter alia, by the significantly broader oval elytra (EW/PW> 1.5 instead of 1.37–1.44 in T. tragelaphus sp. nov.). For differentiation with T. nigrifemoralis sp. nov. and T. balesylvestri sp. nov., see description of the latter species below.
Etymology
Named after the Mountain Nyala (Tragelaphus buxtoni Lydekker, 1910), an endangered and very characteristic large antelope, which occurs in the high-altitude forests of the western Bale Mts together with the 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_023).
Paratypes
ETHIOPIA: 2 ³³, same data as for holotype (CAF, CSCHM).
Description
BODY LENGTH. 4.5–4.6 mm (Ø = 4.53 mm, n = 3).
PROPORTIONS (n = 3). PW/HW = 1.36–1.37 (Ø = 1.37); PW/PL = 1.29–1.31 (Ø = 1.30); PW/PBW = 1.31; EW/PW = 1.37–1.44 (Ø = 1.40); EL/EW = 1.36–1.41 (Ø = 1.39).
COLOUR. Head, pronotum and elytra dark brown, elytra markedly shiny, iridescent. Lateral margin of labrum, palpi, antennal base and legs light brown; antennae distally darkened beginning from second or third antennomere.
MICROSCULPTURE (MALES). Head with rather large, deeply engraved, almost isodiametric meshes on disc and supraorbital area, and smaller, slightly engraved meshes on clypeus. Pronotum with much narrower, finely engraved, transverse meshes. Elytra with hardly visible, very slightly engraved very narrow transverse meshes.
HEAD. Moderately robust. Mandibles moderately short. Labrum with apical margin widely emarginated. Eyes moderately large, convexly protruded. Tempora moderately long, about half as long as eyes, convex, markedly wrinkled to the neck, 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: 1/0.85/1/0.95.
PROTHORAX. Pronotum large, moderately transverse, broadest portion distinctly before middle, base slightly wider than apical margin. Disc moderately convex.Anterior margin slightly concave with anterior angles slightly protruded, rounded. Sides rounded in anterior 6 /7, almost straight before laterobasal angles; latter very obtuse, rounded, not protruded laterally. Marginal gutter narrow in anterior ¾, slightly widened towards base. Base straight in middle, distinctly bent anteriorly near laterobasal angles. Median longitudinal impression very fine, not deepened near base, disappearing at apex; anterior and posterior transverse impressions very shallow, smooth; laterobasal foveae deep, moderately large, roundish, smooth, bordered from the lateral gutter by a fine carina. Pronotum with laterobasal setae present.
PTEROTHORAX. Elytra moderately convex on disc, slightly flattened if viewed from behind, in dorsal view oval, broadest slightly before mid-length, with shoulders broadly rounded; apex suggestively pointed. Striae finely punctate, parascutellar stria moderately short and deep, striae 1–3 moderately fine impressed, 4–6 finer, 7 indistinct, 8 deeply impressed throughout. Internal 3–4 intervals very slightly convex. Recurrent preapical stria deep, short, slightly curved in front, directed to the seventh stria. Third stria with two setiferous dorsal pores (in one specimen the posterior discal pore lacking on right elytron), 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 slightly closer to suture than to elytral apex. Number and positions of the setae of the marginal umbilicate series as in Trechus s. str.
LEGS. Moderately short and thin; protibia slightly dilated towards apex, almost straight, distinctly grooved on external surface. Two basal protarsomeres of male dilated.
MALE GENITALIA. EL/AL = 2.63–2.72 (Ø = 2.68, n = 3). Aedeagal median lobe moderately robust, in lateral view its anterior part wider than basal bulb, its ventral margin more markedly bent behind basal bulb and straight before apex, its dorsal margin convexly widened at apical ostium; apical lamella very short, button-like. Basal bulb moderately small, sagittal aileron moderately large. Endophallus with three more markedly sclerotized folding structures below apical ostium, two of which are longitudinally directed and lie on top of each other, the third one lying in diagonally upright position immediately basad of the latter.
Distribution
Known only from the type locality, a single brook valley in the western Bale Mts above Dodola city. The species was collected at an altitude of approximately 3400–3500 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 64-65, DOI: 10.5852/ejt.2018.446, http://zenodo.org/record/3829902