Black spot on roses. Photo by: Brian Kunkel, Ornamentals IPM Specialist, University of Delaware.

Black spot on rose. Photo by: Division of Plant Industry Archive, Florida Department of Agriculture and Consumer Services, Bugwood.org.

Crabapple scab on crabapple tree leaves. Photo by: Bob Mulrooney, Plant Pathologist, University of Delaware.

Crabapple scab on crabapple fruits. Photo by: Bob Mulrooney, Plant Pathologist, University of Delaware.