Sustainable production of switchgrass and other bioenergy grasses will require eff ective pest management. Identifi cation of potential insect pests and detailed characterization of the plant-insect interaction will better enable us to address emergent insect pests in production fi elds. An added uncertainty is how manipulation of plants for improved quality (e.g. lower lignin) will aff ect plant resistance to insect herbivory. Plants can utilize different mechanisms to defend against chewing versus piercing-sucking insects; however, some basal plant responses appear to be shared across diverse biotic stressors. Th e range and modulation of these responses are beginning to be addressed for several of the temperate, perennial, warm-season grasses that are designated as biomass crops. Other systems have demonstrated the need to become proactive in these studies. For instance, buff alograss, Buchloe dactyloides (Nuttall) Engelmann, was fi rst introduced as a low-maintenance turf species. However, a number of important insect pests were documented within a relatively short time frame. 1,2 Similarly, several recent reports have been published for switchgrass (Panicum virgatum L.) and Miscanthus (Miscanthus x giganteus) that indicate the presence of insect pests in production fi elds, and the overall susceptibility of these species to insect herbivory. 3-9 A number of aphid species can also feed on these perennial grasses. 10 A more detailed evaluation of the suitability and categories of resistance present in tetraploid switchgrasses to feeding by two potential aphid pests have been conducted recently. 11,12 Collectively, these studies demonstrate that the upland switchgrass cultivar, Summer, was generally susceptible to both the greenbug (Schizaphis graminum) and to the yellow sugarcane aphid (Sipha fl ava). Th e lowland switchgrass cultivar, Kanlow was highly resistant to both aphids, indicative of a strong antibiosis response. Interestingly, a population derived