Dalla Torre, 1893: 64; Emery, 1922c: 188; Smith, 1951c: 811 (North America); Ettershank, 1966: 150; Smith, 1979: 1384 (North America); Bolton, 1995b: 424.
Emery, 1922c: 188 (diagnosis); Wheeler, 1931a: 129 (diagnosis, all species key); Creighton, 1957c: 6 (all species key); Ettershank, 1966: 150 (diagnosis, review of genus); Bolton, 1995a: 1053 (census); Baccaro et al., 2015: 280 (genus in Brazil); Cantone, 2017: 250 (brief male diagnosis); Fernández & Serna, 2019: 828 (Colombia species).
Extant: 4 valid species, 1 valid subspecies (6 synonyms, 2 obsolete combinations)