The Cynipidae material studied in this work was collected using Malaise and yellow pan traps in various Corsican oak stands, some of them consisting of Quercus suber and others of Querus ilex. Six Plagiotrochus species P. quercusilicis, P. australis, P. britaniae, P. amenti, P. cardiguensis, and P. vilageliui Pujade-Villar n. sp., one Andricus and eight inquiline species (Ceropres cerri, C. clavicornis, Saphonecrus lusitanicus, Saphonecrus barbotini, Saphonecrus haimi, Synergus ilicinus, Synergus crassicornis, and Synergus apicalis) have been collected. All are recorded for the first time from Corsica. Different nomenclaturial problems in Andricus niger and Plagiotrochus amenti denominations are commented upon. Plagiotrochus amenti Tavares, 1902 is presented as a new synonym of Plagiotrochus amenti Kieffer, 1901. Some specimens of undeterminated Andricus were obtained in floral galls of Q. suber; they are closely related to Andricus niger and A. burgundus. Some specimens obtained from twig galls are morphologically related to Plagiotrochus cardiguensis and are probably conspecific with this species.
Corsica, Cynipidae, Quercus suber, Quercus ilex, Plagiotrochus, Andricus, Ceroptres, Saphonecrus, Synergus.