Infection of potato plants with potato leafroll virus changes attraction and feeding behaviour of Myzus persicae

Potato leafroll virus (PLRV; genus Polerovirus, family Luteoviridae) is a persistently transmitted circulative virus that depends on aphids for spreading. The primary vector of PLRV is the aphid Myzus persicae (Sulzer) (Homoptera: Aphididae). Solanum tuberosum L. potato cv. Kardal (Solanaceae) has a certain degree of resistance to M. persicae: young leaves seem to be resistant, whereas senescent leaves are susceptible. In this study, we investigated whether PLRV-infection of potato plants affected aphid behaviour. We found that M. persicae's ability to differentiate headspace volatiles emitted from PLRV-infected and non-infected potato plants depends on the age of the leaf. In young apical leaves, no difference in aphid attraction was found between PLRV-infected and non-infected leaves. In fact, hardly any aphids were attracted. On the contrary, in mature leaves, headspace volatiles from virus infected leaves attracted the aphids. We also studied the effect of PLRV-infection on probing and feeding behaviour (plant penetration) of M. persicae using the electrical penetration graph technique (DC system). Several differences were observed between plant penetration in PLRV-infected and non-infected plants, but only after infected plants showed visual symptoms of PLRV infection. The effects of PLRV-infection in plants on the behaviour of M. persicae, the vector of the virus, and the implications of these effects on the transmission of the virus are thoroughly discussed.