Isosoma gigantea Ashmead, 1886:127, Holotype ♂; Gates & Hanson, 2009Gates, M.W. & P.E. Hanson 2009. A Revision of Bephrata and Isosomodes (Hymenoptera: Eurytomidae). Journal of Hymenoptera Research 18 (1):25-73.:68, Holotype ♂ (U.S.N.M., No. 2839). - Ashmead, 1886Ashmead, W.H. 1886. Studies on the North American Chalcididae, with descriptions of new species from Florida. Transactions of the American Entomological Society 13:125-135. (distribution). - As Isosomodes gigantea: - Riley et al., 1894Riley, C.V., Ashmead, W.H. & Howard, L.O. 1894. Report upon the Parasitic Hymenoptera of the Island of St. Vincent. Journal of the Linnean Society of London (Zoology) 25:56-61. (distribution); Ashmead, 1894Ashmead, W.H. 1894. Descriptions of new parasitic Hymenoptera. (Paper No. 1). Transactions of the American Entomological Society and Proceedings of the Entomological Section of the Academy of Natural Sciences 21 (3):318-344. (distribution); Howard, 1897Howard, L.O. 1897. On the Chalcididae of the islands of Grenada, B.W.I. Journal of the Linnean Society 26:129-178. (distribution); Dalla Torre, 1898Dalla Torre, C.G. 1898. Catalogus Hymenopterorum hucusque descriptorum systematicus et synonymicus, V. Chalcididae et Proctotrupidae. Sumptibus Guilelmi Engelmann, VII + 598. (distribution); Ashmead, 1900Ashmead, W.H. 1900. Report upon the aculeate Hymenoptera of the islands of St. Vincent and Grenada, with additions to the parasitic Hymenoptera and a list of the described Hymenoptera of the West Indies. Transactions of the Entomological Society of London pt. II:207-367. (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); Gates & Hanson, 2009Gates, M.W. & P.E. Hanson 2009. A Revision of Bephrata and Isosomodes (Hymenoptera: Eurytomidae). Journal of Hymenoptera Research 18 (1):25-73. (distribution); Noyes, 2019Noyes, J.S. 2019. Universal Chalcidoidea Database. World Wide Web electronic publication. :. (distribution). - As Isosomodes giganteus: - Noyes, 2019Noyes, J.S. 2019. Universal Chalcidoidea Database. World Wide Web electronic publication. :. (distribution).
Isosomodes brasiliensis Ashmead, 1904:460, Lectotype ♀, examined (USNM, No. 8077), designated by Gates & Hanson, 2009Gates, M.W. & P.E. Hanson 2009. A Revision of Bephrata and Isosomodes (Hymenoptera: Eurytomidae). Journal of Hymenoptera Research 18 (1):25-73.:68. Synonymized with Isosomodes gigantea (Ashmead, 1886) by Gates & Hanson, 2009Gates, M.W. & P.E. Hanson 2009. A Revision of Bephrata and Isosomodes (Hymenoptera: Eurytomidae). Journal of Hymenoptera Research 18 (1):25-73.:67.