Trechus hagenia 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 hagenia

description: Trechus hagenia sp. nov.
urn:lsid:zoobank.org:act: 33A3D9A9-4941-4BC1-9389-65472E4BF482
Figs 69, 73, 77, 118–119
Diagnosis
Very similar to the allopatric T. bastianinii, but aedeagal median lobe in dorsal view with terminal lamella longer, not widened but almost parallel-sided before apex, with ventral margin longitudinally reinforced keel-like, with a dagger-shaped endophallic copulatory piece, and with a more extensive sclerotization of the anterior portion of the dorsal surface of median lobe, which forms a bowl for the copulatory piece. Also very similar to the allopatric T. colobus sp. nov., but larger and broader on average, with pronotum more transverse, and with aedeagal median lobe more elongated, not sinusoidal, with terminal lamella in dorsal view distinctly broader, and with different folding structures of endophallus. In male genital characters, T. hagenia sp. nov. is very similar to the parapatric T. mekbibi sp. nov., but it differs markedly by the shape of pronotum with smaller base and much smaller laterobasal angles, which are not protruded posteriorly.
Etymology
Named after the African Redwood (Hagenia abyssinica Willd.) which is a nice and very characteristic tree of the montane forests where the new species of Trechus occurs.
Material examined
Holotype
ETHIOPIA: ³, Oromia, 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_016).
Paratypes
ETHIOPIA: 19 ³³, 14 ♀♀, same data as for holotype (CAF, CSCHM); 10 ³³, 9 ♀♀, Harenna Forest, E Rira, alt. 2900 m, 06°44′07″ N, 39°45′59″ E, 9 Feb. 2017 (CAF, CSCHM).
Additional material
ETHIOPIA: 5 ³³, 5 ♀♀, Bale Mts, Harenna Forest, E Rira, alt. 3050–3150 m, 06°44′59″ N, 39°47′36″ E, 12 Feb. 2017 (CAF, CSCHM); 13 ³³, 7 ♀♀, same data as for preceding but Mt Abalk-hasim, river vall., alt. 3250–3450 m, 06°44′34″ N, 39°48′34″ E, Feb. 2007 (CAF, CSCHM).
Description
BODY LENGTH. 4.3–4.7 mm (Ø = 4.52 mm, n = 20).
PROPORTIONS (n = 10). PW/HW = 1.48–1.58 (Ø = 1.51); PW/PL = 1.41–1.53 (Ø = 1.48); PW/PBW = 1.22–1.29 (Ø = 1.26); EW/PW = 1.42–1.53 (Ø = 1.48); EL/EW = 1.29–1.36 (Ø = 1.33).
COLOUR. Head, pronotum and elytra blackish brown, elytra markedly shiny, iridescent, elytral side margin reddish brown lightened. Lateral margin of labrum, palpi, antennal base, legs and sometimes elytral apex, light brown; antennae distally darkened beginning from second or third antennomere (sometimes indistinctly darkened).
MICROSCULPTURE. As described in T. colobus sp. nov.
HEAD. Tempora 0.35–0.45 times as long as eyes; proportions of the first four antennomeres as follows: 1/0.85/1/0.9–1. In all other characters as described in T. colobus sp. nov.
PROTHORAX. Pronotum more transverse, base distinctly wider than apical margin. In all other characters as described in T. colobus sp. nov.
PTEROTHORAX. Elytra slightly flattened on disc; internal 2–3 intervals slightly convex; preapical seta absent (specimen from populations of the type series) or present (specimens from populations occurring east of the type locality, see Additional material above, and Geographical variation below). In all other characters as described in T. colobus sp. nov.
LEGS. As described in T. colobus sp. nov.
MALE GENITALIA. EL/AL = 2.27–2.44 (Ø = 2.35, n = 8). Aedeagal median lobe elongated, in lateral view slightly bent behind basal bulb, with ventral margin slightly convex in middle; ventral margin reinforced keel-like longitudinally (keel bar visible in both ventral and dorsal views as a straight dark longitudinal strip); apical lamella rather long, shortly bent upward at tip, forming a small hook, in dorsal view almost parallel-sided; basal bulb rather small, sagittal aileron rather large. Dorsal surface of median lobe more strongly sclerotized in anterior quarter (just below apical ostium), forming an elongate bowl for the endophallic copulatory piece; the latter in lateral view spine-like, slightly curved, in dorsal view daggerlike with broad base.
Distribution
Endemic to the southeastern slope of the Bale Mts east of Rira village. The species was collected at altitudes of 2900–3300 m.
Geographical variation
The variation of proportions of different body parts is important compared to other species (see Proportions, above). In addition, in populations from the type locality, a river valley on southeastern slope of Bale Mts at a latitude of approx. 39°46′ E, the elytral preapical seta is constantly absent, while farther east, below Mt Abalk-hasim (39°48′34″ E), this seta is present, and in the geographical intermediate population at a latitude of 39°47′36″ E, this seta is absent, present or present on only one elytra.
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 43-49, DOI: 10.5852/ejt.2018.446, http://zenodo.org/record/3829902