Characterizing plant resistance to piercing-sucking insects on switchgrass

Switchgrass, Panicum virgatum L., is a perennial grass native to the North American prairie and has recently been identified as a practical biomass feedstock for energy production. However, the viability of switchgrass as a feedstock will be dependent, at least in part, on effective pest management strategies. To date little is known about the potential insect pests of switchgrass populations being developed for bioenergy production; although, research on related warm-season grasses indicates that insect pests will emerge. Thus, it is important to identify potential insect pests of switchgrass and to describe the plant-insect interactions at multiple ecological levels. In this study, we identified the yellow sugarcane aphid, Sipha flava (Forbes), as one potential pest to switchgrass and set out to better understand the interactions between host plants and piercing-sucking insects. Four switchgrass populations (Kanlow, Summer, K x S, and S x K) were evaluated for resistance and compared with barley, which served as the control. When the four swithchgrass populations were compared with barley, all four were less susceptible to yellow sugarcane aphid feeding. Additionally, significant differences were observed in resistance ratings among the four populations of switchgrass, with Kanlow consistently exhibiting the lowest damage ratings.