The purpose of this application, under Articles 23.9.3 and 75.6 of the ICZN Code, is to conserve the current usage of the generic name Platygaster Latreille, 1809 (Hymenoptera, Platygastridae) by designating a neotype for the type species Scelio ruficornis Latreille, 1805. The current usage of Platygaster is threatened because the name-bearing type of the type species does not match the prevailing concept of Platygaster, but rather matches the concept of Isocybus Foerster, 1856. This would place Isocybus as a junior synonym of Platygaster and require the transfer of more than 650 species from Platygaster to its next junior synonym, Parepimeces Kieffer, 1926, and the transfer of 32 species from Isocybus to Platygaster. In order to prevent confusion and retain nomenclatural stability, we propose a neotype for Scelio ruficornis Latreille, 1805 that is consistent with the prevailing usage of Platygaster.