Do You Know the Way to San Jose?

San Jose Scale is a somewhat overlooked pest that can result in reduced orchard productivity and tree death. Scale literally sucks the juice out of the host plant, including apples and stone fruit. Although generally controlled by spring oil applications, it may become more prevalent during periods of mild winter weather and where pesticide programs become 'softer.' Look for slow, otherwise unexplained, dye-back of shoots and limbs as a sign of scale infestation. Close inspection of the branches during the growing season will reveal the small, white, waxy covering of young scale insects mixed with a sooty black covering as they mature -- it almost looks like a coarse salt and pepper mixture (picture on left, apple branch). Red 'stippling' of fruit at harvest (see picture) is also a good sign of scale infestation. Scale multiplies very rapidly if left unchecked -- good spray coverage and an effective insecticide directed at the crawler stage will help keep San Jose Scale from finding your orchard. For more information, see the Index of Fruit Insect Pest Photographs at West Virginia University, or the April 11, 2005 issue of Scaffolds Fruit Journal.