Hymenopteran parasitoids induce immunosuppression in their host insects in part by the injection of polydnaviruses which target and inhibit both cellular and humoral components of the host response (e.g., Labropoulou et al., 2008) and the parasitized hosts become increasingly susceptible to opportunistic infections by viruses (Rivkin et al., 2006) , bacteria (Shelby et al., 1998) , and other parasitoids (Guzo and Stoltz, 1985) .