AbstractThe effectiveness of resistance of raspberry to the aphid Amphorophora rubi (Kalt.) in restricting the spread of aphid-borne viruses was assessed in a field experiment in Britain using six genotypes of red raspberry. In one block of the experiment, the genotypes alternated with rows of Malling Jewel raspberry infected with 52V, raspberry leaf mottle and raspberry leaf spot viruses, and in the other they alternated with virus-free Malling Jewel. During 4 years, the numbers of A. rubi and the amount of 52 V virus spread in the two blocks were similar, suggesting that this virus was mostly introduced from outside the plots. Lloyd George and Malling Jewel raspberry became heavily infected with raspberry leaf mottle, raspberry leaf spot and 52 V viruses. Glen Clova and Norfolk Giant raspberry, which contain minor genes for resistance to A. rubi, were infested by fewer aphids and virus spread more slowly in these cultivars. A. rubi was rare on Malling Orion and an East Malling raspberry selection (888/49), which have genes A1 and A10, respectively, for resistance to A. rubi, and these plants remained largely free of virus. The role of minor and major gene resistance to A. rubi in restricting virus spread is discussed. A few examples of Macrosiphum euphorbiae (Thos.) and Myzus ornatus Laing were recorded on several of the raspberry genotypes.