INTRODUCTIONNasonia is a complex of four closely related species of wasps with several features that make it an excellent system for a variety of genetic studies. These include a short generation time, ease of rearing, interfertile species, visible and molecular markers, and a sequenced genome. However, the Nasonia species normally are completely or partially reproductively isolated owing to Wolbachia, widespread intracellular bacteria found in arthropods and nematodes. Wolbachia cause cytoplasmic incompatibility (CI) in Nasonia. Although the current genome-sequenced strains of Nasonia (AsymCX, IV7[u], RV2X[u]) are all Wolbachia-free, crosses between infected and uninfected wasps, or between infected wasps of different species, will fail because of Wolbachia. The sperm modification that induces CI appears to be established before the adult stage, so it is generally not possible to cure an infection and break the CI barrier in the same generation. However, a Wolbachia infection can be removed from a strain over a number of generations by feeding antibiotics and selecting on females showing partial CI. This protocol describes the methods to cure a Nasonia strain of its Wolbachia symbionts.