Ischnus jejunus Cresson, 1864:186, ♂. ♂, Illinois (leg. Dr. Samuel Lewis); ♂, Massachusetts (leg. F. G. Sanborn); Heinrich, 1977Heinrich, G.H. 1977. Ichneumoninae of Florida and neighboring states (Hymenoptera: Ichneumonidae, subfamily Ichneumoninae). Arthropods of Florida and neighboring land areas 9:1-350.:50, Holotype ♂ (ANS). - 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. (distribution). - As Coelichneumon jejunus: - Heinrich, 1977Heinrich, G.H. 1977. Ichneumoninae of Florida and neighboring states (Hymenoptera: Ichneumonidae, subfamily Ichneumoninae). Arthropods of Florida and neighboring land areas 9:1-350. (distribution).
Ichneumon apertus Cresson, 1867:293, ♀. 12 ♀♀, Connecticut, New York, Illinois; Heinrich, 1977Heinrich, G.H. 1977. Ichneumoninae of Florida and neighboring states (Hymenoptera: Ichneumonidae, subfamily Ichneumoninae). Arthropods of Florida and neighboring land areas 9:1-350.:50, Holotype ♀ (ANS). - Cresson, 1867Cresson, E.T. 1867. A list of Ichneumonidae of North America, with descriptions of new species. Part I. Transactions of the American Entomological Society 1:289-312. (distribution); Heinrich, 1977Heinrich, G.H. 1977. Ichneumoninae of Florida and neighboring states (Hymenoptera: Ichneumonidae, subfamily Ichneumoninae). Arthropods of Florida and neighboring land areas 9:1-350.:50 ( listed as synonym of Coelichneumon jejunus (Cresson, 1864)); 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.:532 ( listed as synonym of Ischnus jejunus Cresson, 1864).
Coelichneumon duffieldi Heinrich, 1971:965, ♀. Holotype ♀, Letchworth St. Pk., 8-22-1969 (Collection Gerd Heinrich II, leg. R. Duffield); Heinrich, 1977Heinrich, G.H. 1977. Ichneumoninae of Florida and neighboring states (Hymenoptera: Ichneumonidae, subfamily Ichneumoninae). Arthropods of Florida and neighboring land areas 9:1-350.:50, Holotype ♀ (CGH II). Synonymized with Coelichneumon jejunus (Cresson, 1864) by Heinrich, 1977Heinrich, G.H. 1977. Ichneumoninae of Florida and neighboring states (Hymenoptera: Ichneumonidae, subfamily Ichneumoninae). Arthropods of Florida and neighboring land areas 9:1-350.:50.