AbstractThe aim of the study is a review of the sexual generation of European species of the aphid genus Stomaphis Walker. Oviparous females and males of S. (Parastomaphis) longirostris and S. (Stomaphis) radicicola are described and figured in detail. Poorly known sexuales of S. (S.) bratislavensis, S. (S.) quercus, S. (S.) wojciechowskii, S. (P.) graffii, and S. (P.) juglandis are redescribed and figured in detail. Biometric data for the oviparous females and males are reported and keys for the sexual generation of the studied species are provided. On the basis of the morphological characters of the sexuales, supported by biological data, the taxonomic status of the subgenus Parastomaphis Pašek, 1953 stat. rev. is discussed. Aberrations of male morphology are presented, with reference to the general phenomenon of male morphology deterioration in the genus Stomaphis. The discussion also refers to the mating behavior and general evolutionary factors influencing the development of male dwarfism in Stomaphis.