Campoletis sonorensis is an ichneumonid endoparasitoid that harbours a mutualistic relationship with a polydnavirus associated within its genome. Campoletis sonorenisis Ichnovirus (CsIV) genome is approximately 246,707 bp with 5 gene families (the Cys-motif, Rep, Innexin, Viral Ankyrin, & N) and 52 unassigned open reading frames. During oviposition of endoparasitoid egg, CsIV is also injected ,of which, viral genes are expressed inducing a pathology that causes stunting of susceptible lepidopteran larvae and a drastically suppressed immune response. CsIV encodes 10 genes in the cys-motif family all with structural similarity a gene identified from Microplitis croceipes teratocytes,TSP14, which has been shown to suppress H.virescens larvalgrowth and development. Feeding experiments using recombinant CsIV cys-motif proteins (VHv1.1, VHv1.4, WHv1.6, AHv0.8, and AHv1.0) purified from baculovirus expression system was placed on insect diet and shown an effect to slow larval development of lepidopteran hosts. To this point, VHv1.1 has shown the greatest effect in suppressing larval development and caused the highest mortality. Interestingly, larval pupal intermediates were observed and more common in Vhv1.1 protein relative to other cys-motif proteins. In this presentation, we are assessing the insecticidal nature of transgenic tobacco expressing specific CsIV cys-motif genes (VHv1.1, VHv1.4, WHv1.6) by performing leaf disc and full plant feeding bioassays on homozygous and hemizygous plant lines.