Comparative feeding behavior of cereal aphids on switchgrass, Panicum virgatum L

Switchgrass, Panicum virgatum L., is a perennial, polyploid warm-season grass with excellent potential as a biomass crop. To date, little is known about the potential insect pests of switchgrass populations being developed for bioenergy production; however, it is anticipated that bioenergy crops will experience insect-related losses in yields as production is increased. Thus, the long-term sustainability of switchgrass as a bioenergy feedstock will require efforts directed at improved biomass yield under a variety of biotic and abiotic stress factors. Among biotic stressors, aphids are particularly important crop pests, and may cause plant damage by removing nutrients required for plant growth and transmitting plant viruses. Recent work has indicated that both antibiosis and tolerance are important categories of resistance in switchgrass to key aphid crop pests; however, limited information is available on the mechanisms of this resistance. In this study, our goal was to better understand the potential mechanisms involved in insect resistance in switchgrasses and compare Schizaphis graminum and Sipha flava feeding behavior on susceptible and resistant switchgrass populations using electrical penetration graphs.