Maple Bladder Galls: Cosmetic Insect Damage on Autumn Blaze Maple

Maple Bladder Galls: Cosmetic Insect Damage on Autumn Blaze Maple

Tiny, raised red spots (1/16 inch) clustered at the leaf base and along veins on Autumn Blaze maple are bladder galls caused by eriophyid mites. The mites feed on developing leaves, inducing the plant to form hollow pouches. The spots dry and darken by late summer.

Key Points

• Galls are cosmetic; they do not affect tree health or growth.
• No chemical control is needed or recommended.
• Rake and dispose of fallen leaves to reduce mite overwintering sites.
• Mite populations fluctuate yearly; some years are barely noticeable.

Enjoy the tree—this is a natural interaction, not a disease.