Elachista dimicatella sensu auctt.—a complex of neglected species diversity (Lepidoptera, Elachistidae) from European mountain systems

<i>Elachistadimicatella</i> Rebel, 1903, has so far been considered a species in Europe with restricted distribution from Ukraine to western France. The species occurs on mountainous regions. However, the in-depth analysis of a taxonomically uncertain species of <i>Elachista</i> from the Cottian Alps (Italy), especially through DNA barcoding and subsequent morphological studies, led to the realization that individuals previously identified as <i>E.dimicatella</i> from the Cottian Alps and the Pyrenees were misidentified. According to our research, a total of three species can be differentiated: <i>E.dimicatella</i> from Carpathians and its former junior synonym <i>E.niphadophanes</i> Meyrick, 1937, <b>sp. rev.</b>, from the Pyrenees, as well as the newly described <i>E.cottiella</i> <b>sp. nov.</b> from southwestern Alps, hitherto incorrectly identified as <i>E.dimicatella</i>. Diagnostic features of the three species are discussed and illustrated. <i>Elachistadimicatella</i> and <i>E.niphadophanes</i> are redescribed.