Trechus mattisi 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 mattisi

description: Trechus mattisi sp. nov.
urn:lsid:zoobank.org:act: DDAE320F-8BA5-4C34-8DB7-E0C12CB021F9
Figs 1, 5, 9, 37–38
Diagnosis
Within the Ethiopian fauna this species is easily recognized based on a combination of the following characters: (1) body length below 3.5 mm, (2) only the first basal protarsomere of male dilated, (3) mandibles and antennae rather slender, (4) apical margin of labrum moderately emarginated, (5) tempora smooth, (6) pronotum with laterobasal angles markedly developed, slightly obtuse and sharp on tip, (7) internal striae on elytra distinct, (8) elytral preapical seta absent. Trechus mattisi sp. nov. has characters (1)–(5) and (7)–(8) in common with the below described T. transversicollis sp. nov. from the same mountain area, however, it is easily distinguished by darker body colour, pronotum with larger and sharper laterobasal angles and much larger laterobasal foveae, and elytra with two discal setae developed. For additional distinguishing features see diagnosis of the latter species below.
Etymology
This new species is dedicated to Mattis Berndt, youngest son of one of the authors (JS), and helpful companion during the 2017 field work of JS in the Bale Mts.
Material examined
Holotype
ETHIOPIA: ³, Bale Mts, Harenna Forest, E Rira, alt. 3150 m, 06°44′51″ N, 39°46′40″ E, Feb. 2007 (CSCHM, registration number ZSM _COL_2018_001).
Paratypes
ETHIOPIA: 10 ³³, 5 ♀♀, same data as for holotype (CAF, CSCHM); 4 ³³, 4 ♀♀, Harenna Forest, E Rira, alt. 3050–3150 m, 06°44′59″ N, 39°47′36″ E, 12 Feb. 2017 (CAF, CSCHM); 1 ³, same data as for preceding but alt. 2900 m, 06°44′07″ N, 39°45′59″ E, 9 Feb. 2017 (CSCHM); 3 ³³, same data as for preceding but alt. 2690 m, 06°43′25″ N, 39°45′25″ E, 13 Dec. 2017 (CSCHM); 57 exx (³³, ♀♀), Harenna Forest W Rira, alt. 3000 m, 06°45′57″ N, 39°41′47″ E, 14 Dec. 2017 (NHMUK, CAF, CDH, CSCHM, MNHN, ZMAA).
Description
BODY LENGTH. 3.0– 3.4 mm (Ø = 3.12 mm, n = 12).
PROPORTIONS (n = 10). PW/HW = 1.46–1.52 (Ø = 1.48); PW/PL = 1.50–1.61 (Ø = 1.55); PW/PBW = 1.24–1.32 (Ø = 1.27); EW/PW = 1.49–1.63 (Ø = 1.55); EL/EW = 1.14–1.24 (Ø = 1.20).
COLOUR. Head and pronotum brown or dark brown, elytra blackish brown, markedly shiny, elytra slightly iridescent. Clypeus and labrum light brown, palpi, antennal base and legs yellowish; antennae distally indistinctly darkened beginning from distal half of third antennomere.
MICROSCULPTURE. Same in males and females. Head with comparatively large, almost isodiametric meshes on disc and supraorbital area, and smaller meshes on clypeus. Pronotum with somewhat irregularly formed +/- marked transverse meshes, which are deeper engraved near base. Elytra with very finely engraved very narrow transverse meshes.
HEAD. Comparatively robust. Mandibles moderately slender. Labrum with apical margin moderately emarginated. Eyes moderately small, distinctly convexly protruded. Tempora convex, markedly wrinkled to the neck, 0.5–0.6 times as long as eyes, smooth. Frons and supraorbital area strongly convex, with supraorbital furrows almost uniformly bent on disc, deep throughout. Antennae rather slender, proportions of the first four antennomeres as follows: 1/0.93/1/0.87.
PROTHORAX. Pronotum large, markedly transverse, broadest portion distinctly before middle, more markedly narrowed towards apex, base distinctly wider than apical margin. Disc markedly convex. Anterior margin slightly concave with anterior angles broadly rounded and slightly protruded. Lateral margin rounded in anterior ¾ and straight towards laterobasal angles, latter slightly obtuse, sharp at tip, +/- protruded laterally. Marginal gutter narrow in anterior half, distinctly widened towards base. Base straight in middle, very faintly sinusoidal at outer quarter with laterobasal angles sometimes slightly shifted posteriad. Median longitudinal impression fine but distinct, disappearing at apex and base; anterior and posterior transverse impressions shallow and smooth; laterobasal foveae large and smooth, internally distinctly sloped, externally coalescing with the lateral gutter. Pronotum with laterobasal setae present.
PTEROTHORAX. Elytra markedly convex on disc, in dorsal view markedly short and broad, broadest in midlength, with shoulders fully rounded; broadly rounded at apex. Striae indistinctly punctate, parascutellar stria very short or moderately long, striae 1–4 (5) finely or moderately impressed, external stria finer, often indistinct, stria 8 finely impressed at level of the middle group and deeply impressed at level of the subapical group of marginal umbilicate pores. Internal intervals slightly convex. Recurrent preapical stria deep, moderately short, curved in front, directed to the fifth stria. Third stria with two setiferous dorsal pores, the anterior one at anterior elytral quarter, the posterior one at middle; preapical seta absent (but in one specimen present!). Number and positions of the setae of the marginal umbilicate series as in Trechus s. str. (Fig. 9).
LEGS. Short and comparatively thin; protibia slightly dilated towards apex, straight, finely grooved on external surface. Only one basal protarsomere of male dilated.
MALE GENITALIA. EL/AL = 4.24–4.45 (Ø = 4.36, n = 7). Aedeagal median lobe very small, stout, rather weekly sclerotized, in lateral view almost evenly bent throughout; apical lamella short, broadly rounded at tip; basal bulb moderately large, sagittal aileron small and transparent. Endophallus with copulatory piece very weakly sclerotized, in lateral view bag-like, narrowed towards apex.
Distribution
Until now, only found on the southern slope of the Bale Mts east of Rira village at altitudes of 2900– 3150 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 5-7, DOI: 10.5852/ejt.2018.446, http://zenodo.org/record/3829902