Q How do I recognise red berry mite on blackberry?

A The blackberry fruits develop normally but ripen unevenly, so some areas will be fully ripened and black, while other parts will be red and quite hard. Generally, it is the later-formed fruits that are most susceptible to this pest; the earlier fruits invariably escape attack, unless the weather is unusually hot. The damage is caused by a microscopic gall mite, which produces toxins as it sucks the sap. It also feeds on the leaves and flowers, but only causes noticeable symptoms on the
fruits. The plants themselves will look perfectly healthy.

Caption: Red berry mite causes blackberry fruits to ripen unevenly

Q What should I do if my blackberry plants are affected red berry mite?

A Removing infested blackberry canes in late autumn and then keeping the plant well watered, fed and mulched will help to prevent the mites from overwintering, and encourage plenty of new replacement growth.

Q How do I prevent red berry mite on blackberries?

A There are no chemicals available to control red berry mite, but if an infested blackberry is cut
right back to ground level in autumn and the canes are burned, other blackberries in the area will be less likely to become infested.