ABSTRACT
Three key citrus pests, California red scale Aonidiella aurantii (Mask.), citrus thrips Scirtothrips citri (Moult.) and citrus red mite Panonychus citri (McG.), occur in all three of California's major citrus districts. However, in the coastal, intermediate and interior districts, California red scale and many of the other potential pests are under excellent biological control. Citrus thrips is only an occasional pest while citrus red mite is largely an insecticide-induced pest. In the San Joaquin Valley, biological control of California red scale is lacking and citrus thrips is a more consistent pest. Intervention thresholds are assessed by monitoring the flight activity of male California red scale as an index of scale density, and assessing the proportion of fruit infested by citrus thrips and leaves infested by adult citrus red mite as an index of thrips and mite densities.
