Integrated Pest Management of Redberry Mite, Acalitus essigi, on Blackberries

This project identified and assessed the impact of integrated pest management (IPM) strategies on the sustainable control of redberry mite in commercial blackberry production systems in Australia. Monitoring protocols were also developed to enable a more predictive approach to managing redberry mite. Redberry mites are a minute plant-feeding mite in the superfamily Eriophyoidea that infests blackberries in many growing regions. Redberry mite feeding results in the incomplete and/or uneven ripening of blackberry fruit. The damaged fruit is unmarketable resulting in significant crop losses. Several predatory mite species were also assessed in field trials. The results confirmed that Typhlodromalus lailae and T. occidentalis are not effective for controlling redberry mite. However, T. doreenae was isolated on both ripe fruit and within winter buds indicating they do persist in the crop and may impact redberry mite. T. dossei was also commonly observed in fruit sourced from Victoria. Little is currently known about T. dossei except that its presence is commonly associated with high numbers of Eriophyid mites. The spray reduction trial confirmed that the spray program currently used by many Australian producers successfully reduces redberry mite populations but also has severe impacts on predatory mite populations. It was found that the adoption of a ‘softer’ chemical management program reduces redberry mite populations without impacting on predator populations or fruit quality.