Adult psylla are small (up to 0.10 inch long) and hold their transparent wings like a roof over their
dark brown to reddish brown bodies when at rest. A dark spot on the top middle edge of both wings helps
distinguish pear psylla from other psyllids.
Psylla inject into foliage a toxin that can cause blackening and burning. Nymphs also cause the production
of honeydew on fruit and foliage, making them sticky and black with sooty mold. Vegetative growth may
be stunted or entire trees defoliated. Pear psylla also transmit pear decline disease.
Oil sprays applied during the dormant
season will kill many overwintering adults. A second dormant treatment
applied just before bloom can be considered where populations have been high.