The purpose of this application, under Article 23.9.3 of the Code, is to conserve the widely used sawfly generic name Pachynematus Konow, 1890 by giving it precedence over a very rarely used senior subjective synonym Epitactus Förster, 1854, whenever the two are considered to be synonyms. Under Article 24.2, the description of Pachynematus by Konow (1890a) is determined to have conferred availability on the genus name, not the simultaneous description by Konow (1890b). The type species of Pachynematus by subsequent designation of Schmidt et al. (1998) is Nematus trisignatus Förster, 1854, currently regarded as a synonym of Pachynematus clitellatus (Serville, 1823). This species and some of its close relatives are of economic significance as pests of cereal and grass-fodder crops in North America, Europe and China.