AbstractRibosomal DNA from Cecidophyopsis mites from different Ribes species was amplified using the polymerase chain reaction and the products were digested using restriction enzymes. After separating the DNA fragments on gels, it was possible to identify specimens of mites obtained from field samples by comparing the profiles of their DNA banding patterns with those of known Cecidophyopsis species. Using this analysis, a non-gall forming mite found infesting blackcurrant buds in New Zealand was identified as C. grossulariae. On wild Ribes spicatum from Finland showing two sizes of galled buds, C. selachodon was identified in the larger galls located at the tips of branches and a distinct mite in the smaller galls located on the lower parts of the branches. A mite with a DNA banding profile indistinguishable from this latter mite from R. spicatum was also identified in galled buds of blackcurrant genotypes growing in Finland, including those containing C. ribis resistance genes P or Ce. The DNA banding profile of this mite resembled most closely that of C. ribis, but was distinct from it. The occurrence of C. grossulariae and this distinct Cecidophyopsis mite on blackcurrant has implications for the genetic control of Cecidophyopsis mites and possibly for the spread of the reversion disease agent in this crop.