Leaf Galls Caused by Insects: Identification and Management

What You're Seeing

Pod-like growths on leaf tops, formed when insects (mites, midges, aphids) inject hormones into leaf tissue, creating a protective chamber for larvae. The grey bugs inside are the developing insects. The tree may be a grafted ornamental (umbrella form).

Impact and Response

Galls are cosmetic; they rarely threaten tree health. No spray will eliminate existing galls. Rake and destroy fallen galled leaves to reduce next year's population. For heavy infestations, consult an arborist about dormant oil applications before bud break.