Figure 2From: Reproductive mode and fine-scale population genetic structure of grape phylloxera (Daktulosphaira vitifoliae) in a viticultural area in CaliforniaPlot of the principal coordinate analysis (PCA) from the covariance matrix with data standardization calculated using GenAlEx for the grape phylloxera populations from four vineyard-sites in Napa (Oakville) and Yolo (Woodland) counties, California.Back to article page