Trogus atrox Cresson, 1868:93, ♀. Holotype ♀, Dakota Territory (leg. Henry Ulke). - 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). - As Catadelphus atrox: - Hopper, 1939Hopper, H.P. 1939. A synoptical revision of the tribe Trogini Ashmead of the United States and Canada (Hymenoptera: Ichneumonidae). Transactions of the American Entomological Society 65 (4):307-346. (distribution), 342 (comb. nov.); 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).
Trogus marginipennis Cresson, 1868:93, ♂. 2 ♂♂, Dakota Territory (leg. Henry Ulke). Synonymized with Catadelphus atrox (Cresson, 1868) by 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.:535. - 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).