Degree Day Units Are a Bit Less Than Last Year
During 2014 and 2015, abnormally warm weather generated a rapid accumulation of degree day units, well above the 30-year average, that allowed an additional generation of California red scale to complete their development. In addition, the excessively warm winters we have had during those years allowed California red scale, and other pests, to continue to develop during the winter in the San Joaquin Valley. This is quite unusual. While the 2016 season was well above the 30-year average through August, the accumulated degree day units at the end of the season were less than the last two years. Hopefully we will have a cold (but not freezing) winter that will prevent California red scale populations from continuing their development and cause mortality to the younger instars.