Baehria separata Schmidt & Faille, sp. nov.

Faille, Arnaud, Hofmann, Sylvia, Merene, Yeshitla, Hauth, David, Opgenoorth, Lars, Woldehawariat, Yitbarek & Schmidt, Joachim, 2023, Explosive radiation versus old relicts: The complex history of Ethiopian Trechina, with description of a new genus and a new subgenus (Coleoptera, Carabidae, Trechini), Deutsche Entomologische Zeitschrift 70 (2), pp. 311-335 : 311

Baehria separata Schmidt & Faille, sp. nov.

Figs 4-7 , 8-15

Type material.

Holotype male, with label data: Ethiopia, Amhara, Mt. Choke, crater valley, alt. 3780-3900 m, 10°42'12"N, 37°50'58"E, 27.II.2019, leg. D. Hauth, J. Schmidt, Yeshitla M., Yitbarek W. (CSCHM).

Paratypes: 39 males, 54 females, same data as holotype (CAF, CSCHM, NHMAA); 2 males, Mt. Choke, crater valley, alt. 3700-3800 m, 10°41'14"N, 37°50'07"E, 24.II.2019, leg. D. Hauth, J. Schmidt, Yeshitla M., Yitbarek W. (CSCHM); 6 males, 7 females, Mt. Choke, western crater valley, alt. 3500-3600 m, 10°41'00"N, 37°50'35"E, 01.V.2022, leg. J. Schmidt, Yeshitla M., (CSCHM).

Additional material.

3 males, 3 females, W-slope Mt. Choke , alt. 3370 m, 10°38'07"N, 37°45'51"E, 23.II.2019, leg. D. Hauth, J. Schmidt, Yeshitla M., Yitbarek W. (CAF, CSCHM) ; 6 males, 7 females, W-slope Mt. Choke , alt. 3700-3900 m, 10°42'17"N, 37°50'29"E, 25.II.2019, leg. D. Hauth, J. Schmidt, Yeshitla M., Yitbarek W. (CAF, CSCHM) ; 43 males, 31 females, W-slope Mt. Choke , "Shoa Kidaneberet" valley, alt. 3700-3800 m, 10°39'08"N, 37°49'45"E, 8.V.2022, leg. J. Schmidt, Yeshitla M. (CSCHM) ; 10 males, 10 females, N-slope Mt. Choke , alt. 3800-3950 m, 10°43'16"N, 37°51'15"E, 26.II.2019, leg. D. Hauth, J. Schmidt, Yeshitla M., Yitbarek W. (CSCHM) ; 18 males, 20 females, N-slope Mt. Choke , alt. 3750-3850 m, 10°43'51"N, 37°52'15"E, 09.V.2022, leg. J. Schmidt, Yeshitla M. (CSCHM) ; 3 males, 2 females, N-slope Mt. Choke , above Gumadur, alt. 3750-3850 m, 10°44'10"N, 37°53'48"E, 05.V.2022, leg. J. Schmidt, Yeshitla M. (CSCHM) ; 1 male, N-slope Mt. Choke , N of Waber, alt. 3450-3600 m, 10°44'48"N, 37°46'22"E, 07.V.2022, leg. J. Schmidt, Yeshitla M. (CSCHM) ; 13 males, 5 females, Mt. Choke , eastern crater valley, alt. 3700-3800 m, 10°42'59"N, 37°54'13"E, 06.V.2022, leg. J. Schmidt, Yeshitla M. (CSCHM) .

Etymology.

The specific epithet refers to the markedly separated distributional area of the taxon, which is, based on current knowledge, far away from its next relatives. It is built by the past participle of the Latin verb separare.

Description.

See description of genus.

Body length: 6.9-7.5 mm ( Ø = 7.19 mm, n = 20).

Proportions (n = 20): PW/HW = 1.18-1.25 ( Ø = 1.21); PW/PL = 1.30-1.38 ( Ø = 1.34); PW/PBW = 1.48-1.54 ( Ø = 1.50); PBW/PAW = 0.92-1.00 ( Ø = 0.96); EW/PW = 1.42-1.48 ( Ø = 1.45); EL/EW = 1.46-1.56 ( Ø = 1.51).

Colour: Dark brown to blackish, moderately shiny in both sexes; palpi light brown, labrum and scapus reddish brown, basal 3/4 of femora light brown; antennal base in some specimens more widely brightened.

Microsculpture: Same in males and females. Head with deeply engraved, rather large, almost isodiametric sculpticells on disc and supraorbital area, slightly smaller sculpticells on clypeus. Pronotum with moderately deep engraved, slightly transverse sculpticells on disc and markedly deep engraved sculpticells near base; the sculpticells are somewhat smaller than on head disc. Elytral intervals with more finely engraved sculpticells which are more transverse than on pronotum.

Aedeagus. Proportion EL/AL (n = 10): 2.40-2.64 ( Ø = 2.52). Median lobe in lateral view unevenly bent, dorsally with a distinct concavity before middle (Fig. 14 ), in dorsal view not or very slightly broadened before apex (Fig. 15 ).

Differential diagnosis.

See Diagnosis and Identification sections of the genus, above.

Distribution and geographical variability.

The type series was collected on the western side of the crater valley of Mt. Choke. Additional populations were collected on the north eastern side of the crater valley and on northern and western slopes of Mt. Choke. Specimens of these populations differ +/- distinctly from those of the type series and from each other by the curvature of the aedeagal median lobe, the number of lightened basal antennomeres, and the depth of the engraving of the elytral microsculpture. Slight differences were also found in the DNA sequence segments of the three investigated specimens representing three different populations (Fig. 2 ; Suppl. material 1). Further morphological and molecular genetic studies are needed to answer the question of whether certain populations represent separate species or subspecies.

Habitat.

Specimens of Baehria separata gen. nov., sp. nov. have been found in stone packs traversed by running water in small steep streams in the afroalpine zone, together with Dytiscidae beetles (Fig. 16 ). Based on this finding, Baehria separata gen. nov., sp. nov. seems to be adapted to a rheophilic way of life.

Trechus Clairville, 1806

Figures

Figure 2. Ultrametric time-calibrated phylogeny of Trechini beetles and outgroups (basal part of the tree, continues in Fig. 3). The tree was obtained from BEAST 2 based on the concatenated sequence data and using two age constraints (for details see text). Black circles and stars at branch nodes refer to posterior probabilities ≥ 0.98 and bootstrap values> 75, respectively. Grey bars specify the 95 % HPD of the respective node age. Collapsed, colored trechine clades refer to previous results of Faille et al. (2013). The southern hemisphere Duvaliomimus - Paratrechus clade with the Ethiopian endemic Baehria gen. nov. is highlighted ochre.

Figure 16. North-exposed slope on Mt. Choke with Erica forest and a steep small brook at an altitude of 3600 m during dry season (May, 2022). The stone pack in the brook is habitat of Baehria separata Schmidt & Faille, gen. nov., sp. nov.: the beetles were collected between the stones along which the water flows (in order to find the beetles, the creek bed was partially dug up).

Figures 4 - 7. Baehria separata Schmidt & Faille, gen. nov., sp. nov., dorsal aspect of body (4, 6) and head (5, 7) of paratypes; 4, 5. Male; 6, 7. Female. The small white circles in Figs 5 and 7 mark the insertion points of the clypeal setae.

Figures 8 - 15. Baehria separata Schmidt & Faille, gen. nov., sp. nov. 8. Left and right mandible, dorsal aspect; 9. Ventral aspect of head; the small white circles mark the insertion points of the setae on submentum; 10. Right male protarsomeres, left latero-ventral aspect; 11. Left male metatarsomeres, right lateral aspect; 12. Right male protibia, dorsal aspect; 13. Anterior part of elytra and pronotal base; the arrows point to the insertions of the anterior elytral discal setae; 14. Aedeagus, left lateral aspect; 15. Aedeagus, dorsal aspect.