Spider mites (family Tetranychidae) are among the most widespread and troublesome grape arthropod pests in California. The vast majority of mite research efforts on grapes in California have been with Pacific mite (Tetranychus pacificus), although the dominant mite pest in the grape growing regions of the Sierra foothills, the west side of the San Joaquin Valley, and the North and Central Coast is Willamette mite (Eotetranychus willametti). Pacific mite has been shown to reach higher densities under heavy applications of sulfur (used for control of powdery mildew (Uncinula necator), and is associated with vine stresses, yet little work in these areas has been conducted on Willamette mite. We established studies at two different field sites on the Central Coast and compared 1) the effect of sulfur dust vs. synthetic fungicides and 2) the effect of 80%, 60%evapotranspiration (ET) irrigation deficits compared to 100% ET. Results will be discussed in terms of Willamette mite density, grape yield and vigor, and wine quality.