The type localities, depositary museums, taxonomical comments and host plants of the species of Hylaeus Fabricius, 1793, the unique genus of the Hylaeinae in the Neotropical Region, are mentioned. Lectotypes of the following species are designated: Prosopis bothros Schrottky, 1910; Prosopisfissa Vachal, 1901; Prosopis itapuensis Schrottky, 1906; Prosopis opaca Schrottky, 1906; Prosopis opaciventris Friese, 1925; Prosopis paraguayensis Schrottky, 1906; Prosopis recisa Vachal, 1910; Prosopis scabra Vachal, 1909; Prosopis sculptilis Schrottky, 1910; Prosopis tricolor Schrottky, 1906 and Prosopis trivittata Friese, 1916. The following ones are recognized as new combinations; Hylaeus petroselini (Schrottky, 1906); Hylaeus polybioides (Schrottky, 1906), Hylaeus polybiaeformis (Schrottky, 1907) and Hylaeus psammophilus (Schrottky, 1906).
Hymenoptera; Colletidae; Hylaeinae; Hylaeus; Neotropical
