Pear Psylla (PP) is an aggressive pest of pears in Washington State. It feeds from phloem tissue in shoots and leaves. The pear tree is very sensitive to this type of feeding and responds with black, necrotic patches on the leaves followed by leaf abscission. Honeydew excreted by the insects builds up on fruit and will cause tiny black necrotic spots. Honeydew also serves as a medium for sooty mold, which appears in cool weather. PP are very fecund and biological controls rarely reduce a population in a commercial orchard where trees are kept at high vigor. Therefore, growers typically follow an intense spray schedule.
