Mutilla gracilis Smith, 1855:42, ♂. ♂, Brazil (Para) (leg. H.W. Bates). - Blake, 1871Blake, C. 1871. Synopsis of the Mutillidæ of North America. Transactions of the American Entomological Society 3:217-265. (distribution); Blake, 1879Blake, C.A. 1879. Catalogue of the Mutillidae of North America, with descriptions of new species. Transactions of the American Entomological Society 7:243-254. (distribution); Cameron, 1888-1900Cameron, P. 1888-1900. Biologia Centrali-Americana - Insecta. Hymenoptera. (Fossores) Vol. II. R. H. Porter and Dulau & Co., London. 413pp, 14 pl.:313 (listed); Cameron, 1894Cameron, P. 1894. Biologia Centrali-Americana. Insecta. Hymenoptera. (Fossores) Vol. II. :258-330. (distribution); Dalla Torre, 1897Dalla Torre, C.G. 1897. Catalogus hymenopterorum hucusque descriptorum systematicus et synonymicus. Volumen VIII: Fossores (Sphegidae). Breitkopf & Härtel, Leipzig. 1-749. (distribution); Fox, 1899Fox, W.J. 1899. The North American Mutillidae. Transactions of the American Entomological Society 25:219-300. (distribution); Cresson, 1902Cresson, E.T. 1902. Descriptions of some Mutilla from Brazil. Transactions of the American Entomological Society 28:1-82. (distribution). - As Ephuta gracilis: - Pagliano et al., 2020Pagliano G., D.J. Brothers, R. Cambra, A.S. Lelej, P. Lo Cascio, M.M. Palmerini, P.L. Scaramozzino, K.A. Williams & M. Romano 2020. Checklist of names in Mutillidae (Hymenoptera), with illustrations of selected species. Bolletino del Museo Regionale di Scienze naturali Torino 36 (1-2):5-425. (distribution).