Currants are subject to a variety of insect and disease pests. Affected buds swell, form dried rosettes, and fail to break during following spring. Whole stem becomes blind and dies back to ground. Plant should be removed and burned immediately upon detection. Aphids commonly distort currant foliage causing red spots.
Spider mites are common and also cause foliar distortion.
Clear-winged borers lay their eggs on stems in late spring. The larvae hatch and bore into the stems where they remain until the following season. An infestation is usually detected only after the stem wilts and dies. Borers will spread and generally cause loss of whole a planting without quick control. Cut out affected stems, search for others and spray.