The identity of Eulamprotes libertinella auctt. is revised. Morphological characters and supplementing sequences from the barcode region of mt COI (Cytochrome c Oxidase 1) gene give evidence to at least two well supported species: E. libertinella (ZELLER, 1872) and the newly described E. occidentella n. sp. from the south-western Alps of France and Italy (Cottian Alps) where both taxa may occur syntopically. A lectotype of Gelechia (Argyritis) libertinella ZELLER 1872 is designated. E. libertinella in a strict sense is recorded in four genetic lines on an alpine scale, a situation which is however not reflected by different morphology.