Blackcurrant gall mite – Cecidophyopsis ribis (Westw.), harmfulness and possibility to control with fenpyroximate (Ortus 05 SC)

Summary The blackcurrant gall mite (big bud mite) – Cecidophyopsis ribis (Westw.) is the most dangerous pest of blackcurrant in many countries. C. ribis is a key pest in Poland and causes severe damage on some plantations, destroying even more than 50% of the buds. The big bud mite infests most of the commonly grown cultivars and only a few are resistant. Looking for new possibilities to control the pest is still necessary. The experiments were carried out at the Research Institute of Horticulture in 2008–2011. Fenpyroximate active substance in Ortus 05 SC showed high effectiveness in reducing the number of the blackcurrant gall mites emerging from treated buds. Ortus 05 SC (1.25; 1.5 l/ha) and Ortus 05 SC (1.5 l/ha) + Slippa (0.1 l/ha) applied 3 times during migration of the big bud mite, reduced the number of damaged buds by 76–90% compared to the control bush. Also Ortus 05 SC (1.5 l/ha), applied twice: at the beginning and during the full blossom of black currant significantly reduced the number of buds infested by the big bud mite. On the bushes where Ortus 05 SC (1.5 l/ha) + Slippa (0.1 l/ha) were used twice, slightly less damaged buds compared with the treatments without wetting were reported, but the differences were not statistically significant.