Zethus lævinodus Smith, 1857:17, ♀. ♀, Mexico (B.M.); Bequaert, 1928Bequaert, J.C. 1928. A study of certain types of diplopterous wasps in the collection of the British Museum. The Annals and Magazine of Natural History ser. 10: v. 2 (7):138-176.:154, Holotype ♀ (British Museum); Stange, 1997Stange, L.A. 1997. The Zethus of Venezuela (Hymenoptera: Eumenidae). Insecta Mundi 11 (3-4):311-324.:313, Holotype ♀ (BMNH). - Stange, 1997Stange, L.A. 1997. The Zethus of Venezuela (Hymenoptera: Eumenidae). Insecta Mundi 11 (3-4):311-324. (distribution); Carpenter et al., 2012Carpenter, J.M., B.R. Garcete-Barrett & Y.J.A.F. López 2012. Las Vespidae (Hymenoptera: Vespoidea) de Guatemala. In: Cano, E.B. & J.C. Schuster (Ed.). Biodiversidad de Guatemala. Volumen 2. 269-279. (distribution). - As Zethus levinodus: - Dalla Torre, 1894Dalla Torre, C.G. 1894. Catalogus Hymenopterorum hucusque descriptorum systematicus et synonymicus, IX. Vespidae (Diploptera). Guilelmi Engelmann, 181. (distribution). - As Zethus levinodus: - Dalla Torre, 1894Dalla Torre, C.G. 1894. Catalogus Hymenopterorum hucusque descriptorum systematicus et synonymicus, IX. Vespidae (Diploptera). Guilelmi Engelmann, 181. (distribution).
Zethus nitidinodus Cameron, 1907:81, ♂. Holotype ♂, Mexico; Bequaert, 1928Bequaert, J.C. 1928. A study of certain types of diplopterous wasps in the collection of the British Museum. The Annals and Magazine of Natural History ser. 10: v. 2 (7):138-176.:154, Holotype ♂ (British Museum). Synonymized with Zethus laevinodus Smith, 1857 by Bequaert, 1928Bequaert, J.C. 1928. A study of certain types of diplopterous wasps in the collection of the British Museum. The Annals and Magazine of Natural History ser. 10: v. 2 (7):138-176.:154.