Ionympha Graham is removed from synonymy with Asecodes Förster. Teleopterus Silvestri, Metasecodes Erdös and Desmatocharis Graham are placed in synonymy with Asecodes. These transpositions are supported by new characters. Five species previously classified in Teleopterus are newly transferred to Asecodes: Desmatocharis reticulatus Kamijo, Entedon erxias Walker, Eulophus turcicus Nees, Teleopterus delucchii Boucek, T. politus Hansson. The Nearctic species of Asecodes are presented in a key, including one new species: A. orilatum, two newly recorded species: A. mento (Walker), A. coronis (Walker), hitherto known only from Europe, and two species previously in Teleopterus: A. erxias, A. politum. Ionympha is represented by two species in the Nearctic: I. carne (Walker), I. ochus (Walker).