Simulated environmental temperature rise may alter pest relative dominance by modifying species interaction in an aphid community

Global warming is predicted to increase mean temperature affecting species interactions, including those among co-existing aphids in crop fields. These interactions can influence aphid community dynamics and their impacts on crops. Most previous studies concerning the warming effects on aphids have focussed on a single species or tested the thermal responses of different species separately, overlooking how interspecific interactions might alter the relative dominance of aphid communities under warming conditions. Consequently, the impact of modified species interactions on aphid communities in warming climates remains unclear. To investigate this, we conducted an experiment with five mean temperature levels using four cereal aphid species [Metopolophium dirhodum (Walker), Rhopalosiphum padi (Linnaeus), Sitobion avenae (Fabricius) and Schizaphis graminum (Rondani)] (all Hemiptera: Aphididae) under both conditions of with and without species interactions. Our results showed that changes in mean temperature and species interactions significantly altered the relative dominance of aphid communities. Specifically, the presence of species interactions facilitated population growth of two species (R. padi and S. graminum), whereas it depressed that of the other two (M. dirhodum and S. avenae). Importantly, the relative dominance of these species changed as temperature increased. Our study thus emphasizes that both climate warming and species interactions might be key drivers shifting the relative dominance and community structure of co-existing aphid pests, and more broadly, of many other co-occurring species in natural and agricultural ecosystems.