Insect hosts have evolved innate immunity against infection by parasitoids wasp, and in co-evolutionary relationship parasitoids have also developed effective strategies to overcome host immune systems.Adult females of Nasonia vitripennis inject the key virulence factor, venom along with eggs into their hosts, the pupae of Musca domestica.Here, we investigate the influences of N.vitripennis venom on the gene expression profile of host hemocytes.