Differential performance and behavior of the corn leaf aphid, Rhopalosiphum maidis, on three species of the biomass crop miscanthus
Résumé
Miscanthus, a perennial C4-grass, is identified as a promising candidate for biomass production owing to its high yield potential under low nitrogen input and its low susceptibility to diseases and pests. However, some significant insect pests of conventional cereal grain crops such as the corn leaf aphid (Rhopalosiphum maidis) are able to develop on miscanthus. In the prospect of extensive planting of miscanthus for bioenergy, this may lead to the worsening of pest problems in the surrounding conventional crops. The aim of this study was to assess, through laboratory experiments, the ability of R. maidis to colonize three main miscanthus species studied in Europe for biomass production, i.e., Miscanthus x giganteus, M. sacchariflorus, and M. sinensis. In this purpose, comparative analyses of aphid's performance and plant penetration behavior were performed. Despite an altered plant penetration behavior on miscanthus, R. maidis was able to colonize (i.e., to develop and reproduce) the three miscanthus species tested and exhibited a behavior adapted to the transmission of both persistent and non-persistent phytoviruses. M. sacchariflorus and, to a lesser extent, M. sinensis were found less suitable and acceptable host plant for R. maidis than M. x giganteus. Results are discussed in terms of agronomic risks and implications for miscanthus improvement programs.