Spraying trials have been conducted in southern California over a period of three years concerning control of the grape bud mite, a physiological strain of the grape erineum mite–Eriophyes vitis– (Pgst.). During this period approximately 55 acres of plots have failed to provide information concerning the prevention by spraying of the injury caused by this mite. This is because of the erratic nature of the appearance of bud mite symptoms.