Recent developments in museomics enable genetic information to be recovered from previously unusable collection specimens and thus to answer complex taxonomic questions. Here we apply museomics to a taxonomic problem involving several species ofArgyriaHubner (Pyraloidea, Crambinae), with previously unrecognized morphological variation. By analysing the DNA barcode (COI-5P) in numerous specimens, we aimed to reconstruct phylogenetic relationships between species, to provide better evidence for synonymies, and to circumscribe their geographical distribution. Using an innovative DNA hybridization capture protocol, we partially recovered the DNA barcode of the lectotype ofArgyria lacteella(Fabricius, 1794) for comparison with the 229 DNA barcode sequences ofArgyriaspecimens available in the Barcode of Life Datasystems, and this firmly establishes the identity of the species. The same protocol was used for the following type specimens: theArgyria abronalis(Walker, 1859) holotype, thus confirming the synonymy of this name withA. lacteella, the holotype ofA. lusella(Zeller, 1863),rev. syn., the holotype ofA. multifactaDyar, 1914,syn. n., newly synonymized withA. lacteella, and a specimen ofArgyria diplomochalisDyar, 1913, collected in 1992. A complementary sampling composed of nine specimens ofA. lacteella,A. diplomochalis,A. centrifugensDyar, 1914 andA. gonogrammaDyar, 1915, from North to South America, were integrated using classical COI amplification and Sanger sequencing.Argyria gonogrammaDyar, described from Bermuda, is the name to be applied to the more widespread North American species formerly identified asA. lacteella. Following morphological study of its holotype,Argyria vestalisButler, 1878,syn. n.is also synonymized withA. lacteella. The nameA. pusillalisHubner, 1818, is considered a nomen dubium associated withA. gonogramma. The adult morphology is diagnosed and illustrated, and distributions are plotted forA. lacteella,A. diplomochalis,A. centrifugens, andA. gonogrammabased on slightly more than 800 specimens. For the first time, DNA barcode sequences are provided for the AntilleanA. diplomochalis. Our work highlights the efficiency of the DNA hybrid capture enrichment method to retrieve DNA barcodes from 18th and 19th century type specimens in order to solve taxonomic issues in Lepidoptera.