Cucurbit plant species and virus infection shape the aphid-associated microbiome

Aphis gossypii Glover, is a global agricultural insect pest that can damage cultivated plants directly via sap-sucking, and indirectly by transmitting viral diseases. In particular, it is the most abundant aphid species colonizing cucurbit crops in the Mediterranean Basin, with the subsequent occurrence of aphid-transmitted viruses. Accumulating evidence has revealed that the insect-associated microbiome is an important component of the physiological fitness of pest insects, including reproduction, development, growth, immunity, and behavior, as well as the transmission of plant viruses. However, how plant host species and viral infections could influence and shape the aphid microbiome has yet to be explored. Here, we investigated the microbiome of A. gossypii clon before and after feeding on different cucurbit plants (melon and cucumber), including infected melon plants with watermelon mosaic virus (WMV, non-persistent) and cucurbit aphid-borne yellows virus (CABYV, persistent) in single and mixed infections.