The grape leaf rust mite, Calepitrimerus vitis (Nalepa), was first discovered in the interior of British Columbia in 2009 on grape leaves from a commercial vineyard north of Osoyoos. Bronzing of grape leaves confirmed to be caused by C. vitis in summer 2009 was followed by severely stunted shoots and distorted leaves in several vineyards in spring 2010. Numbers and lengths of shoots and fruit clusters were reduced significantly on vines infested with C. vitis. Earlier studies have shown that outbreaks of C. vitis result from pesticide sprays targeted to other pests that damage predator mite populations. Sprays of sulphur-based fungicides early in the season are the recommended method of control
