Influence of Previous Infestation of Wheat Leaves and Ears by Sitobion avenae on Interaction with Rhopalosiphum padi

Abstract

Interactions betweoen living organisms of different species may be negative or positive for the interaction partners, as these species may hinder or help each other. Plant sap-feeding insects, such as aphids, may indirectly interact with other species feeding on the same plant at the same time by causing changes to the shared host plant and potentially affecting the performance of and the balance between the species. We compared the colony sizes of two species of grain aphids, which were infesting leaves or ears of wheat at the same time. The wheat plants had either been previously infested by one of the two species or kept uninfested, to determine if a previous infestation affects interaction with the other species. Colony sizes of the pre-infesting aphid species were increased on the previously infested plants at some time points. There were only minor changes in the balance of the two species. With the findings derived from this study, we can better understand the interactions between two important cereal pest species. Our findings are important from an agricultural perspective, as wheat is an important crop plant species that may suffer from infestation by different aphid species.