Cucurbit aphid-borne yellows virus(CABYV) modifies the alighting, settling and probing behaviour of its vectorAphis gossypiifavouring its own spread

Abstract

Plant pathogens are able to influence the behaviour and fitness of their vectors in such a way that changes in plant–pathogen–vector interactions can affect their transmission. Such influence can be direct or indirect, depending on whether it is mediated by the presence of the pathogen in the vector's body or by host changes as a consequence of pathogen infection. We report the effect that the persistently aphid-transmitted Cucurbit aphid-borne yellows virus (CABYV, Polerovirus) can induce on the alighting, settling and probing behaviour activities of its vector, the cotton aphid Aphis gossypii. Only minor direct changes on aphid feeding behaviour were observed when viruliferous aphids fed on non-infected plants. However, the feeding behaviour of non-viruliferous aphids was very different on CABYV-infected than on non-infected plants. Non-viruliferous aphids spent longer time feeding from the phloem in CABYV-infected plants compared to non-infected plants, suggesting that CABYV indirectly manipulates aphid feeding behaviour through its shared host plant in order to favour viral acquisition. Viruliferous aphids showed a clear preference for non-infected over CABYV-infected plants at short and long time, while such behaviour was not observed for non-viruliferous aphids. Overall, our results indicate that CABYV induces changes in its host plant that modifies aphid feeding behaviour in a way that virus acquisition from infected plants is enhanced. Once the aphids become viruliferous they prefer to settle on healthy plants, leading to optimise the transmission and spread of this phloem-limited virus.