Mutilla forreri Cameron, 1894:290, ♂. ♂, Mexico, Presidio de Mazatlan, Ventanas in Durango (leg. Forrer); Mickel, 1938Mickel, C.E. 1938. The Neotropical mutilid wasps of the genus Timulla Ashmead (Hymenoptera:Mutillidae). Transactions of the Royal Entomological Society of London 87 (22):529-680.:570, Type ♂ (British Museum (Natural History), London). - Cameron, 1888-1900Cameron, P. 1888-1900. Biologia Centrali-Americana - Insecta. Hymenoptera. (Fossores) Vol. II. R. H. Porter and Dulau & Co., London. 413pp, 14 pl.:290 (listed); Dalla Torre, 1897Dalla Torre, C.G. 1897. Catalogus hymenopterorum hucusque descriptorum systematicus et synonymicus. Volumen VIII: Fossores (Sphegidae). Breitkopf & Härtel, Leipzig. 1-749. (distribution). - As Timulla prominens forreri: - Mickel, 1938Mickel, C.E. 1938. The Neotropical mutilid wasps of the genus Timulla Ashmead (Hymenoptera:Mutillidae). Transactions of the Royal Entomological Society of London 87 (22):529-680. (distribution), 570 (comb. nov.); Cambra & Quintero, 1993Cambra, R.A. & Quintero, D. 1993. Studies on Timulla Ashmead (Hymenoptera: Mutillidae): New distribution records and synonymies, and descriptions of previously unknown Allotypes. The Pan-Pacific Entomologist 69 (4):299-313. (distribution); Maes, 1999 1999. Catalogo de los insectos y artropodos terrestres de Nicaragua. Volumen III. León, Nicaragua. 1170-1898. (distribution); 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).
Mutilla chroma Cameron, 1894:291, ♂. ♂, Mexico, Presidio de Mazatlan (leg. Forrer); Mickel, 1938Mickel, C.E. 1938. The Neotropical mutilid wasps of the genus Timulla Ashmead (Hymenoptera:Mutillidae). Transactions of the Royal Entomological Society of London 87 (22):529-680.:570, Type (British Museum (Natural History), London). Synonymized with Timulla prominens forreri (Cameron, 1894) by Mickel, 1938Mickel, C.E. 1938. The Neotropical mutilid wasps of the genus Timulla Ashmead (Hymenoptera:Mutillidae). Transactions of the Royal Entomological Society of London 87 (22):529-680.:570. - Cameron, 1888-1900Cameron, P. 1888-1900. Biologia Centrali-Americana - Insecta. Hymenoptera. (Fossores) Vol. II. R. H. Porter and Dulau & Co., London. 413pp, 14 pl.:291 (listed); Dalla Torre, 1897Dalla Torre, C.G. 1897. Catalogus hymenopterorum hucusque descriptorum systematicus et synonymicus. Volumen VIII: Fossores (Sphegidae). Breitkopf & Härtel, Leipzig. 1-749. (distribution); 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.:269 ( listed as synonym of Timulla prominens forreri (Cameron, 1894)).