In Scotland, Phyllocoptes gracilis (Nal.) is widespread on cultivated and wild raspberries. However, in studies in 1969-75, feeding damage to leaves and fruits was usually observed only on raspberries grown in sheltered situations, where mites tended to aggregate. Female mites overwintered in the buds, under bud scales or in petiole scars. In the spring, they dispersed to the emerging foliage of the fructo-canes where they fed and oviposited. Populations reached a maximum on the fructo-canes in mid-July, when the first fruits were maturing, and on the primo-canes in late September. Migration to the overwintering sites began in late September. Cultivars differed in the extent to which they supported overwintering populations and show symptoms of infestation.