Trechus transversicollis, Schmidt & Faille, 2018

Schmidt, Joachim & Faille, Arnaud, 2018, Revision of Trechus Clairville, 1806 of the Bale Mountains and adjacent volcanos, Ethiopia (Coleoptera, Carabidae, Trechini), European Journal of Taxonomy 446, pp. 1-82: 9-11

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Trechus transversicollis

sp. nov.

Trechus transversicollis   sp. nov.

Figs 2 View Figs 1–4 , 6 View Figs 5–8 , 10 View Figs 9–12 , 39 View Figs 37–56


This new species has more diagnostic characters in common with the above described T. mattisi   sp. nov. (for details see above) than with any other species of the Ethiopian fauna. It is easily distinguished from the latter by the lighter colour of body, narrower meshes of pronotal microsculpture, larger eyes, pronotum with much more obtuse laterobasal angles, with basal margin laterally shifted anteriad, and with much smaller laterobasal foveae, and by the elytra with a single dorsal seta.


The specific epithet refers to the markedly transverse pronotum of the new species.

Material examined


ETHIOPIA: ³, Bale Mts , Harenna Forest, E Rira, alt. 2690 m, 06°43′25″ N, 39°45′25″ E, Feb. 2007 ( CSCHM, registration number ZSM _COL_2018_002).



ETHIOPIA: 1 ³, same data as for holotype ( CAF); 21 ³³, 18 ♀♀, same data as for preceding but 13 Dec. 2017 ( NHMUK, CAF, CDH, CSCHM, MNHN, ZMAA).


BODY LENGTH. 2.65 mm.

PROPORTIONS. PW/HW = 1.50; PW/PL = 1.59; PW/PBW = 1.24; EW/PW = 1.41; EL/EW = 1.29.

COLOUR. Head, pronotum, and elytra light brown, very shiny, appendages yellowish, but antennae distally indistinctly darkened beginning from third antennomere.

MICROSCULPTURE (MALE). Very slightly engraved on whole body surface. Head with comparatively large, almost isodiametric meshes on disc and supraorbital area, and smaller meshes on clypeus. Pronotum with very narrow, elytra with extremely narrow (hardly visible) 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, 0.35 times as long as eyes, smooth. Clypeus, frons and supraorbital area very markedly convex; supraorbital furrows uniformly bent on disc, very deep throughout, foveate on level of supraorbital setae. Antennae rather slender, proportions of the first four antennomeres as follows: 1/1/1/0.75.

PROTHORAX. Pronotum large, markedly transverse, broadest portion slightly before middle, more markedly narrowed towards apex, base distinctly wider than apical margin. Disc markedly convex. Anterior margin slightly concave with anterior angles moderately protruded. Lateral margin rounded throughout, laterobasal angles obtuse, blunt at tip. Marginal gutter narrow throughout. Base slightly convex in middle, distinctly shifted anteriorly at outer quarter. Median longitudinal impression fine but distinct, disappearing at apex and base; anterior transverse impression indistinct, smooth, posterior transverse impression broad but shallow in middle, slightly rugose towards base; laterobasal foveae very small, pit-like. Pronotum with laterobasal setae present.

PTEROTHORAX. Elytra markedly convex on disc, in dorsal view short and broad, broadest in mid-length, with shoulders fully rounded; broadly rounded at apex. Striae finely punctate, parascutellar stria short, striae 1–4 moderately impressed, stria 5 finer, 6–7 indistinct, 8 moderately impressed from level of the middle group of the subapical group of marginal umbilicate pores towards apex. Internal intervals slightly convex. Recurrent preapical stria deep, moderately short, curved in front, directed to the fifth stria. Third stria with a single setiferous dorsal pore at anterior elytral quarter; posterior dorsal seta and preapical seta absent. Number and positions of the setae of the marginal umbilicate series as in Trechus   s. str. ( Fig. 10 View Figs 9–12 ).

LEGS. As described in T. mattisi   sp. nov.

MALE GENITALIA. EL/AL = 5.16. Aedeagal median lobe markedly small, stout, weakly sclerotized, in lateral view almost evenly bent throughout; apex very broad, rounded; basal bulb and saggital aileron rather small; endophallic copulatory piece very weakly sclerotized, sack-like shaped.


Known only from the southern slope of the Bale Mts, east of Rira village, at an altitude of 2690 m.


Bavarian State Collection of Zoology


Natural History Museum, London


Museum National d'Histoire Naturelle