Transmission of Hop Latent and Hop Mosaic Carlaviruses by Macrosiphum euphorbiae and Myzus persicae

Macrosiphum euphorbiae and Myzus persicae, polyphagous aphid species commonly found within hop gardens in Australia, were confirmed as vectors of hop latent virus (HpLV) and hop mosaic virus in glasshouse trials. Both vectors transmitted either virus with equivalent efficiency. This is the first record of HpLV transmission by an aphid other than Phorodon humuli. Furthermore, aphids feeding on single infected plants, sequentially on plants infected with one virus and then the other or on co-infected source plants did not influence transmission efficiency of either virus, nor was the frequency of co-transmission affected by the order of virus acquisition. The role of these vectors in carlavirus epidemics in Australian hop gardens is discussed