Exetastes obscurus Cresson, 1865:281, ♀. Holotype ♀, Colorado Territory, 1864 (leg. Mr. James Ridings); Cushman, 1937Cushman, R.A. 1937. Revision of the North American species of Ichneumon-flies of the genus Exetastes Gravenhorst. Proceedings of the United States National Museum 84 (3017):243-312, 6 pl.:276, Type (Acad. Nat. Sci. Philadelphia, no. 1609). - Ashmead, 1894Ashmead, W.H. 1894. Some parasitic Hymenoptera from Lower California. Proceedings of the California Academy of Sciences 2 (4):122-129. (distribution); Dalla Torre, 1901-1902Dalla Torre, C.G. 1901-1902. Catalogus Hymenopterorum hucusque descriptorum systematicus et synonymicus. — Volumen III: Trigonalidae, Megalyridae, Stephanidae, Ichneumonidae, Agriotypidae, Evaniidae, Pelecinidae. Pars II. Breitkopf & Härtel, Leipzig. VIII + 1141. (distribution); Cushman, 1937Cushman, R.A. 1937. Revision of the North American species of Ichneumon-flies of the genus Exetastes Gravenhorst. Proceedings of the United States National Museum 84 (3017):243-312, 6 pl. (distribution); Krombein et al., 1979Krombein, K.V., P.D. Hurd, D.R. Smith & B.D. Burks 1979. Catalog of Hymenoptera in America North of Mexico. Volume 1. Symphyta and Apocrita (Parasitica). Smithsonian Institution Press, Washington D.C. 1-1198. (distribution); Ruíz-Cancino et al., 2002Ruíz-Cancino, E., D.R. Kasparyan & J.M. Coronado Blanco 2002. Ichneumonidae. In: Llorente Bousquets, J. & J.J. Morrone (Ed.). Biodiversidad, taxonomía y biogeografía de artrópodos de México: Hacia una síntesis de su conocimiento, volumen III. 631-646. (distribution); Khalaim & Ruiz-Cancino, 2012Khalaim, A.I. & Ruiz-Cancino, E. 2012. Mexican species of Exetastes (Hymenoptera: Ichneumonidae: Banchinae), with description of three new species. Revista Mexicana de Biodiversidad 83:370-379. (distribution).
Exetastes decoloratus Cresson, 1865:280, ♂. Holotype ♂, Colorado Territory, 1864 (leg. Mr. James Ridings); Cushman, 1937Cushman, R.A. 1937. Revision of the North American species of Ichneumon-flies of the genus Exetastes Gravenhorst. Proceedings of the United States National Museum 84 (3017):243-312, 6 pl.:276, Type (Acad. Nat. Sci. Philadelphia, no. 1616). Synonymized with Exetastes obscurus Cresson, 1865 by Cushman, 1937Cushman, R.A. 1937. Revision of the North American species of Ichneumon-flies of the genus Exetastes Gravenhorst. Proceedings of the United States National Museum 84 (3017):243-312, 6 pl.:276. - Dalla Torre, 1901-1902Dalla Torre, C.G. 1901-1902. Catalogus Hymenopterorum hucusque descriptorum systematicus et synonymicus. — Volumen III: Trigonalidae, Megalyridae, Stephanidae, Ichneumonidae, Agriotypidae, Evaniidae, Pelecinidae. Pars II. Breitkopf & Härtel, Leipzig. VIII + 1141. (distribution); Krombein et al., 1979Krombein, K.V., P.D. Hurd, D.R. Smith & B.D. Burks 1979. Catalog of Hymenoptera in America North of Mexico. Volume 1. Symphyta and Apocrita (Parasitica). Smithsonian Institution Press, Washington D.C. 1-1198.:577 ( listed as synonym of Exetastes obscurus Cresson, 1865).
Exetastes fascipennis Howard, 1903:pl. 10, fig. 7 - Cushman, 1937Cushman, R.A. 1937. Revision of the North American species of Ichneumon-flies of the genus Exetastes Gravenhorst. Proceedings of the United States National Museum 84 (3017):243-312, 6 pl.:276 ( listed as synonym of Exetastes obscurus Cresson, 1865).