Silencing RpadOrco disrupts host seeking, semiochemical avoidance and reproductive fitness in Rhopalosiphum padi.

The odorant receptor co-receptor (Orco) is an important component of the insect olfactory system. However, the biological functions of Orco in the bird cherry-oat aphid, Rhopalosiphum padi, remain unclear, particularly its roles in olfactory perception, host-plant selection and aphid fitness. RpadOrco was predominantly expressed in the antennae. RNA interference-mediated knockdown of RpadOrco significantly reduced electroantennogram responses to 11 behaviorally relevant odorants, including plant volatiles, the repe…