Technical Abstract: Anthocyanins are likely a visual aid for attracting pollinators. However, there is also the possibility that anthocyanins are present in some flowers as defensive molecules protecting them from excess light, pathogens or herbivores. In this study, resistance due to anthocyanins from commercial petunia flowers (Petunia hybrida) was examined for insecticide/antifeedant activity against corn earworm (CEW, Helicoverpa zea) and cabbage looper (CL, Trichoplusia ni). The petunia flowers studied contained a star pattern, with colored and white sectors. CEW larvae ate significantly less colored sectors than white sectors in most cases. All CEW larvae feeding on blue sectors weighed significantly less after two days than larvae feeding on white sectors, which was negatively correlated with total anthocyanin levels. CL larvae ate less of blue sectors than white sectors, and blue sectors from one petunia cultivar caused significantly higher CL mortality than white sectors. Partially purified anthocyanin mixtures isolated from petunia flowers, when added to insect diet discs at approximately natural concentrations, significantly inhibited both CEW and CL larva development. These studies demonstrate that the colored sectors of these petunia cultivars slow the development of these lepidopteran larvae and indicate that anthocyanins play some part in flower defense in petunia.