A new synonym for Zelia Robineau-Desvoidy, 1830 (Diptera, Tachinidae), the genus Opsozelia Townsend, 1919, with the description of three new species.

The monotypic tachinid genus Opsozelia Townsend, 1919 (Diptera: Tachinidae) is synonymized with ZeliaRobineau-Desvoidy 1830, syn. nov. The single species of Opsozelia, O. discalis Townsend, 1919, is redescribed as Zelia discalis, comb. nov., based on examination of the holotype from Guyana and additional material from Suriname, Brazil and Paraguay. Three new species of Zelia similar to Z. discalis are described from Brazil: Z. magna sp. nov., Z. guimaraesi sp. nov. and Z. formosa sp. nov. These four species are treated informally as the Zelia discalis species group. An identification key to the species of this species group is provided based on male specimens. Descriptions and illustrations are provided for the male terminalia of all species and for the female terminalia of one species, Z. guimaraesi.