Mesostenus thoracicus Cresson, 1864:314, ♂♀.N. Y. (leg. Grote);Penn. (leg. Cresson);Delaware (leg. Dr. Wilson); Townes & Townes, 1962Townes, H.K. & M. Townes 1962. Ichneumon-flies of America north of Mexico: 3. Subfamily Gelinae, tribe Mesostenini. Bulletin of the United States National Museum 216 (3):1-602.:450, Lectotype ♀ (Philadelphia). - Cresson, 1872Cresson, E.T. 1872. Hymenoptera Texana. Transactions of the American Entomological Society 4:153-292. (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); Viereck, 1905Viereck, H.L. 1905. Notes and descriptions of Hymenoptera from the Western United States, in the collection of the University of Kansas. Transactions of the Annual Meetings of the Kansas Academy of Science 19:264-326. (distribution); Cushman, 1929Cushman, R.A. 1929. A revision of the North American Ichneumon-flies of the genus Mesostenus and related genera. Proceedings of the United States National Museum 74 (art. 16):1-58. (distribution); Townes & Townes, 1962Townes, H.K. & M. Townes 1962. Ichneumon-flies of America north of Mexico: 3. Subfamily Gelinae, tribe Mesostenini. Bulletin of the United States National Museum 216 (3):1-602. (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); Rodríguez-Mota et al., 2015Rodríguez-Mota, A.J., E. Ruíz-Cancino, A.I. Khalaim, J.M. Coronado-Blanco & J. Treviño-Carreónj 2015. Diversidad de Ichneumonidae (Hymenoptera) en un bosque de Pinus spp. y Juniperus flaccida en Jaumave, Tamaulipas, México. Revista Mexicana de Biodiversidad 86:972-980. (distribution).
Mesostenus erythrogaster Ashmead, 1890:406, Townes & Townes, 1962Townes, H.K. & M. Townes 1962. Ichneumon-flies of America north of Mexico: 3. Subfamily Gelinae, tribe Mesostenini. Bulletin of the United States National Museum 216 (3):1-602.:450, Type ♂ (Washington). Synonymized with Mesostenus thoracicus Cresson, 1864 by Cushman, 1929Cushman, R.A. 1929. A revision of the North American Ichneumon-flies of the genus Mesostenus and related genera. Proceedings of the United States National Museum 74 (art. 16):1-58.:41. - 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); Townes & Townes, 1962Townes, H.K. & M. Townes 1962. Ichneumon-flies of America north of Mexico: 3. Subfamily Gelinae, tribe Mesostenini. Bulletin of the United States National Museum 216 (3):1-602.:450 ( listed as synonym of Mesostenus thoracicus Cresson, 1864).