Polydnaviruses (PDVs) have an obligate mutualistic association with some members of the Ichneumonidae and Braconidae families of parasitic wasps. PDVs have an unusual lifecycle. Viral replication occurs in the wasp mutualist, while the pathogenic effects of the virus only occur in the Lepidopteran host. CsIV the prototype Ichnovirus is characterized by a large multisegmented genome which contains five putative gene families that encode multiple gene variants. Functional characterization of the gene families and their role in immunosuppression is complicated by the limitations of the virual life cycle. We are evaluating the potential for the Junonia coenia densovirus (JcDNV) vector to overcome some of these limitations. The JcDNV vector contains viral non-structural genes and a C-terminal DsRED fusion in the viral structural genes. Studies suggest that the vector stably integrates within chromosomes of insect cells as well as insect embryos. We have constructed a JcDNV vector containing an RNAi expression cassette specific for the cys-motif gene, VHv1.4. Preliminary data suggests that this vector integrates into Sf9 and Tn5 cells and Heliothis virescens embryos. We are now constructing JcDNV vectors containing expression cassettes for members of the vankryn gene family. This vector shows promise for enabling systematic knockout or overexpression of individual members of viral gene families and thereby functionally characterizing the roles of PDV gene families during viral infection.