Diploidy restoration in Wolbachia-infected Muscidifurax uniraptor (Hymenoptera:pteromalidae)

Thelytokous reproduction, where females produce diploid female offspring without fertilization, can be found in many insects. In some Hymenoptera species, thelytoky is induced by Wolbachia, a group of cytoplasmically inherited bacteria. We compare and contrast early embryonic development in the thelytokous parthenogenetic species Muscidifurax uniraptor with the development of unfertilized eggs of the closely related arrhenotokous species, Muscidifurax raptorellus. In the Wolbachia-infected parasitic wasp M. uniraptor, meiosis and the first mitotic division occur normally. Diploidy restoration is achieved following the completion of the first mitosis. This pattern differs in the timing of diploidy restoration from previously described cases of Wolbachia-associated thelytoky. Results presented here suggest that different cytogenetic mechanisms of diploidy restoration may occur in different species with Wolbachia-induced thelytoky. (C) 2002 Elsevier Science (USA). All rights reserved.