More than 30 virus or virus-like diseases are reported to occur in Ribes and Rubus crops worldwide and a few of these are of important economic significance in Europe. In Ribes, the major pathological problem is blackcurrant reversion virus [blackcurrant reversion associated virus] and its eriophyid gall mite vector, Cecidophyopsis sp., both of which cause serious damage. The only other virus disease of significance is gooseberry vein banding [? gooseberry vein banding associated virus]. Effective control of reversion disease and of the blackcurrant gall mite vector seems very promising using plant genes for resistance to these organisms. However, the species structure, ecology and virus vector capabilities of the different eriophyid mites occurring on Ribes species needs to be studied in more detail to assess the likely stability of currently deployed mite resistance genes. In Rubus, the most widespread virus and the most difficult to control is the pollen-borne raspberry bushy dwarf virus. Cultivars with resistance genes to common isolates of this virus are effective in preventing infection but the occurrence of resistance-breaking (RB) isolates pose serious problems for control. Because of the lack of suitable sources of resistance to these RB isolates in Rubus germplasm, engineered resistance using viral genes may offer the most appropriate means of control. Aphid-borne viruses, once controlled very effectively in the UK through the use of cultivars carrying genes for resistance to the main aphid vector, Amphorophora idaei, are now increasing in incidence due to the ability of aphid biotypes to overcome these resistance genes. The A. idaei-transmitted viruses causing raspberry leaf spot mosaic disease are the most damaging in sensitive raspberry cultivars and their spread is not controlled effectively by the application of aphicides. No genes for resistance to these viruses are known but the inheritance of sensitivity to infection with some viruses is determined by single dominant genes, offering the possibility of breeding plants for tolerance to infection. Raspberry vein chlorosis virus, transmitted by the small raspberry aphid, Aphis idaei, is increasing in incidence in some cultivars posing problems for control, but strong resistance or immunity to the virus is present in some R. idaeus var. strigosus [R. strigosus] cultivars. Nematode-borne viruses are very damaging when they occur in crops, but they are usually very localized in occurrence. However, these viruses may become of more widespread significance following the withdrawal of commonly used soil sterilants in horticulture.