Spider mites [including Tetranychus pacificus McGregor (Pacific mite) and T. turkestani Ugarov & Nikolski (strawberry mite)] are the most important invertebrate pests of the roses (Rosa hybrida) grown in Kern County, Calif. (the major production area in the United States). However, sampling methods and treatment thresholds have been subjective. A rapid presence–absence field sampling method has been developed, and treatment thresholds for mites have been evaluated based on the method. Roses exhibit a higher tolerance for spider mite populations than previously thought.