Ailment Comparison Guides

Learn the key differences between oak wilt and anthracnose, two common causes of leaf browning and defoliation in oak trees across the United States.

Compare two of North America's most destructive invasive wood-boring insects: the emerald ash borer and the Asian longhorned beetle.

Understand the differences between Dutch elm disease and spongy moth damage, two major threats that can cause severe defoliation and tree death.

Compare fire blight and beech leaf disease, two serious plant diseases that cause distinctive browning patterns but affect entirely different tree species.

Compare hemlock woolly adelgid and bagworm, two small pests that can be difficult to spot but cause serious damage to evergreen trees.

Compare two major invasive insects in the eastern United States: the spotted lanternfly and the Japanese beetle, both of which damage a wide range of plants.

Learn to distinguish between powdery mildew and anthracnose, two common fungal diseases that affect the leaves of many tree and shrub species.

Compare two deadly oak diseases: oak wilt and sudden oak death. Learn the geographic, symptomatic, and diagnostic differences that set them apart.

Compare two significant fungal diseases of trees: armillaria root rot, which attacks roots, and fusiform rust, which deforms stems and branches of southern pines.

Learn to distinguish cedar-apple rust from apple scab, two common fungal diseases that affect apple and crabapple trees but have very different symptoms and management strategies.