One feature that has been in the Callery pear tree’s favor is its relative resistance (immunity?) to insects and diseases; but enthusiasm for that feature may now be dampened by the occurrence of pear trellis rust caused by Gymnosporanium sabinae. The fungus-related to the cedar-apple rust pathogen-has become widespread in western Europe, and has been reported in parts of Canada, the U.S. Pacific Northwest and in recent years, Michigan. Beginning in 2009, unusually colorful (yellow to purple-red) leaf lesions were noted on some ornamental Callery pear in scattered locations in southeastern New York.