Response of the bird cherry-oat aphid (Rhopalosiphum padi) to climate change in relation to its pest status, vectoring potential and function in a crop-vector-virus pathosystem

Global climate change threatens world food production via direct effects on plant growth and alterations to pest and pathogen prevalence and distribution. Complex relationships between host plant, pest, pathogen and environment create uncertainty particularly involving vector-borne diseases. We attempt to improve the understanding of the effects of climate change via a detailed review of one crop-vector-pathogen system.The bird cherry-oat aphid, Rhopalosiphum padi, is a global pest of cereals and vector of yellow dwarf viruses that cause significant crop losses in cereals. R. padi exhibits both sexual and parthenogenetic reproduction, alternating between crops and other host plants. In Australia, only parthenogenesis occurs due to the absence of the primary host, thus the aphid continuously cycles from grasses to cereals, allowing for continuous virus acquisition and transmission.We have reviewed the potential impact of future climate projections on R. padi population dynamics, persistence, abundance, dispersal and migration events as well as the interactions between vector, virus, crop and environment, all of which are critical to the behaviour and development of the vector and its ability to transmit the virus. We identify a number of knowledge gaps that currently limit efforts to determine how this pathosystem will function in a future climate.