Cryptus hirtifrons Ashmead, 1889:411, ♂. Holotype ♂, Texas; Cushman, 1927Cushman, R.A. 1927. Miscellaneous notes and descriptions of Ichneumon-flies. Proceedings of the United States National Museum 72 (2709):1-22.:7, Type ♂ (U.S.N.M., No. 2028); 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.:38, Type ♂ (Washington). - As Apsilops hirtifrons: - Ashmead, 1896Ashmead, W.H. 1896. Descriptions of new parasitic Hymenoptera. Transactions of the American Entomological Society and Proceedings of the Entomological Section of the Academy of Natural Sciences 23:179-234. (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); 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). - As Trichocryptus hirtifrons: - Cushman, 1927Cushman, R.A. 1927. Miscellaneous notes and descriptions of Ichneumon-flies. Proceedings of the United States National Museum 72 (2709):1-22. (distribution).
Cryptus cyaniventris Riley, in Riley & Howard, 1890:154, sex not indicated Nomen nudum. Synonymized with Trichocryptus hirtifrons (Ashmead, 1889) by Cushman, 1927Cushman, R.A. 1927. Miscellaneous notes and descriptions of Ichneumon-flies. Proceedings of the United States National Museum 72 (2709):1-22.:7. Nomen nudum. - Riley & Howard, 1890Riley & Howard 1890. Some of the bred parasitic Hymenoptera in the National Collection (Continued from p. 18). Insect Life 3 (4):151-158. (distribution).Cryptus cyaniventris Riley, in Riley & Howard, 1890:154, sex not indicated Nomen nudum. Synonymized with Trichocryptus hirtifrons (Ashmead, 1889) by Cushman, 1927Cushman, R.A. 1927. Miscellaneous notes and descriptions of Ichneumon-flies. Proceedings of the United States National Museum 72 (2709):1-22.:7. Nomen nudum. - Riley & Howard, 1890Riley & Howard 1890. Some of the bred parasitic Hymenoptera in the National Collection (Continued from p. 18). Insect Life 3 (4):151-158. (distribution).