Discovery of a new blind ground beetle in western French Pyrenees, and its relevance to the phylogeny of Pyrenean hypogean Trechini.

Geotrechus sarpedon sp. n., a new species of blind Trechini is described from Arbailles Massif, western Pyrenees, trance. The generic attribution of the new species was challenging as it shares morphological features of both genera Geotrechus Jeannel, 1919 and Aphaenops subgenus Hydraphaenops Jeannel, 1926, confirming their polyphyly, which has been highlighted by previous molecular studies on the group. Molecular data suggests unambiguously strong affinities between the new species and the clade Aphaenops vasconicus Jeannel, 1913-A. galani Espanol, 1968 occurring in the same geographic area, and not related with Aphaenops ehlersi (Abeille de Perrin, 1872), type species of the subgenus Hydraphaenops. The species is included in the paraphyletic genus Geotrechus until its affinities with the other species of Geotrechus and A. (Hydraphaenops) are clarified.

Molecular phylogeny of the Trechus brucki group, with description of two new species from the Pyreneo-Cantabrian area (France, Spain) (Coleoptera, Carabidae, Trechinae).

A molecular phylogeny of the species from the Trechus brucki clade (previously Trechus uhagoni group)based on fragments of four mitochondrial genes and one nuclear gene is given. We describe Trechus (Trechus) bouillonisp. n. from the western pre-Pyrenees: Sierras de Urbasa-Andía, Navarra, Spain. The species was collected in mesovoid shallow substratum (mss), a subterranean environment. Molecular as well as morphological evidences demonstrate that the new species belongs to the Trechus brucki clade. A narrow endemic species of high altitude in western French Pyrenees merged with Trechus brucki Fairmaire, 1862a, Trechus bruckoidessp. n., is described. A lectotype is designated for Trechus brucki and Trechus planiusculus Fairmaire, 1862b (junior synonym of Trechus brucki). The species group is redefined based on molecular and morphological characters, and renamed as the brucki group, as Trechus brucki was the first described species of the clade. A unique synapomorphy of the male genitalia, a characteristic secondary sclerotization of the sperm duct, which is shared by all the species of the brucki group sensu novo, is described and illustrated. The Trechus brucki group sensu novo is composed of Trechus beusti (Schaufuss, 1863), Trechus bouillonisp. n., Trechus brucki, Trechus bruckoidessp. n., Trechus grenieri Pandellé, 1867, T. uhagoni uhagoni Crotch, 1869, T. uhagoni ruteri Colas, 1935 and Trechus pieltaini Jeannel, 1920. We discuss the taxonomy of the group and provide illustrations of structures showing the differences between the species, along with distribution data and biogeographical comments.