DictyodesMalloch, 1933 (Diptera: Sciomyzidae) is a new synonym of RetelliaRobineau-Desvoidy, 1830, with Retellia claropunctataRobineau-Desvoidy, 1830 (Tetanocera) serving as the type species of Retellia. Steyskal's (1974) analysis is confirmed, that Malloch (1933) redescribed Tetanocera dictyodesWiedemann, 1830 [as Dictyodes dictyodes] from a specimen that Malloch misidentified as T. dictyodes but which was, in fact, an undescribed species. Retellia platensis (Steyskal, 1974) (Dictyodes) new combination is confirmed as a new synonym of Retellia lacera (Wiedemann, 1830) (Tetanocera) new combination; a lectotype and a paralectotype are designated for the latter species. Steyskal's (1974) designation of Pherbina cayennensisRobineau-Desvoidy, 1830, an unplaced but possibly related species, as a nomen dubium is supported. A key to distinguish species of Retellia from similar-looking species in the Neotropical Region and a key to the two valid species of Retellia are provided. Relationships among Retellia and other genera of Sciomyzidae are discussed.