Maple Tree Black Eggs: Gall Mites, Not Eggs

Autumn Blaze Maple Covered in Tiny Black "Eggs"

Every leaf covered. Owner asks what they are and what to do.

Identification: Gall Mites

Not eggs—galls from eriophyid mites. Types: bladder gall (green→red→black globes), spindle gall (elongate spikes), erineum gall (red felt patches). Mites overwinter under bark, move to new leaves in spring. Galls enclose mites; mating/egg-laying inside.

Impact

Generally not harmful. Heavy infestation may reduce photosynthesis/growth slightly.

Management

Chemical control seldom needed. If desired, apply registered insecticide for eriophyid mites in mid-April before buds swell (adults moving to new growth).