Source: Howard F. Schwartz, Colorado State University, Bugwood.org
Although it is not particularly common, pear scab is very destructive when it does occur. Its symptoms and disease cycle are so similar to those of apple scab that they need not be repeated here.
A major difference is the frequent appearance of pear scab on twigs, where it can overwinter and start new infections in spring.
Routine fungicide sprays normally control this disease in Pennsylvania.