This review provides descriptions, color habitus photos, illustrations, a key for identification, and summaries of distributions and host plants for all known species of the genus Erythridula (135 species). E. canadensis sp.n. from British Columbia (Canada), E. planerae sp. n. from southern Illinois (USA), and E. wyatti sp. n. from southeastern USA are described as new; 129 new synonyms are recognized; a lectotype is designated for Typhlocyba obliqua var. dorsalis Gillette; neotypes are designated for E. lloydi Hepner and E. lasteri Hepner; E. rhodedendronae Hepner is emended to E. rhododendronae Hepner.