Cacopsylla pyricola Foerster
Hemiptera: Sternorrhyncha: Psyllidae
Adults (A) resemble very small cicadas and can be reddish brown (overwintered generation) or tan to light brown (summer forms). Smaller, wingless nymphs are yellow with red eyes, flat and oval in shape, and develop within a clear honeydew drop (B). Larger "hard shell" nymphs are darker, with black areas interspersed with green or brown coloration (C); these forms have noticeable wing pads and are free-living.
Widespread and a major pest in most fruit-growing states and provinces in eastern North America.
Attacks pear exclusively. Motile stages are "flush feeders" that suck sap from newer, tender growth, and secrete excess fluid as honeydew. This collects on leaves and fruits, provides a good medium for sooty mold growth (D). Psylla feeding can kill leaf tissue (called "psylla scorch") in sunny, dry conditions. Excessive feeding and injection of toxic saliva can cause wilting and premature leaf drop.
The apple sucker (Psylla mali) is closely related, but can be distinguished by its lighter coloration and the fact that it does not occur on pear.
Spring egg-laying can be suppressed by prebloom oil applications. Diligent hand removal of suckers can greatly reduce psylla populations. A balanced fertilizer program and avoidance of excessive nitrogen greatly reduces flush vegetative growth that attracts psylla. Many predacious insects are natural enemies, but commercial production often requires applications of broad-spectrum insecticides, highly refined summer oil, kaolin clay or insecticidal soap.
The MSU IPM Program maintains this site as an access point to pest management information at MSU. The IPM Program is administered within the Department of Entomology, fueled by research from the AgBioResearch, delivered to citizens through MSU Extension, and proud to be a part of Project GREEEN.