The effects of antifeedant compounds and mineral oil on stylet penetration and transmission of potato virus Y by Myzus persicae (Sulz.) (Hom., Aphididae)

Plant‐derived antifeedant compounds and mineral oil were applied to tobacco leaves infected by potato virus Y (PVY), in order to assess the effects on stylet penetration behaviour and subsequent transmission of the virus by the aphid vector, Myzus persicae. Video recordings of insect movements at the leaf surface showed that the initiation of stylet penetration was significantly delayed when mineral oil (Sunoco 7E) was present, but behaviour was not affected by any of three antifeedant treatments (quassin, hop α‐acids or hop β‐acids). Each insect was monitored until it had withdrawn its stylets from the leaf, and was then transferred to a healthy tobacco test seedling in order to determine its ability to transmit the virus. The proportion of aphids transmitting PVY from antifeedant‐treated plants was similar to that from solvent‐treated control plants, but the mineral oil caused a clear reduction in virus transmission efficiency.