Dryberry mite

Dryberry mite feeds on black raspberry leaves and fruit in Western Washington, causing berries to dry and fail to ripen properly. You will see affected fruits become hard, desiccated, and not the plump berries expected. Damage becomes obvious at harvest time when berries fail to develop normal quality. Economic impact is moderate to severe in commercial plantings; home gardens tolerate light infestations.

No effective chemical control for this mite is widely available. Remove and destroy heavily infested canes in late fall or winter to eliminate overwintering sites. Maintain adequate soil moisture during the growing season; water-stressed plants are more susceptible. Plant resistant varieties if available. Improve air circulation through pruning to create less favorable conditions for the mite. Most home growers accept some berry damage as the cost of growing raspberries.