Introduction: Pear scab is an economically important disease throughout the world and can cause serious losses on susceptible cultivars. The disease is more of a problem in European countries than in North America, and is especially of major concern in Japan. Sometimes called black spot, pear scab resembles apple scab (Venturia inaequalis) in nearly all respects, and is caused by the closely related fungus, V. pirina. Pear cultivars differ in susceptibility to scab; however, cultivars resistant in one region of the country may not be resistant in another region.