SAMPLING AND TREATMENT THRESHOLDS FOR SPIDER-MITE MANAGEMENT IN FIELD-GROWN ROSE PLANTS

Spider mites [including Tetranychus pacificus McGregor (Pacific mite) and T. turkestani Ugarov & Nikolski (strawberry mite)] are the most im portantinvertebrate pests of the roses (Rosa hybpida) grown in Kern Co unty, Calif, (the major production area in the United States). However , sampling methods and treatment thresholds have been subjective, A ra pid presence-absence field sampling method has been developed, and tre atment thresholds for mites have been evaluated based on the method. R oses exhibit a higher tolerance for spider mite populations than previ ously thought.