Blister mite
Eriophyes spp.
1 host plant
Last updated
Raised, blister-like bumps on leaf surfaces, often reddish or yellowish green, indicate blister mite feeding inside the leaf tissue. You will see these galls appearing on fruit tree and ornamental leaves from mid-spring onward as overwintering mites emerge from bud scales and begin feeding on expanding leaves. The blisters eventually turn brown or black as the season progresses.
Dormant oil applied during late winter before bud break smothers overwintering mites under bud scales. Once mites are inside the leaf blisters, they are protected from contact sprays. Damage is almost always cosmetic on established trees and does not affect overall plant health. Predatory mites help suppress populations naturally through the growing season.
Quick Reference
Adults of these mites (Eriophyidae) are very tiny and can be seen only under magnification. They are light to amber yellow, cylindrical, tapered at the posterior end, with two pairs of short legs at the front of the body. The overall appearance is that of a small worm. Immatures appear similar to the adult but are smaller. Feeding on leaves causes reddish to yellowish green blisters; blisters turn brown or black as the tissue dies later in the season. Leaves may drop prematurely. Loss of...
Cultural Controls
- Phytoseiid predatory mites almost always keep mites under control if broad-spectrum insecticide applications are avoided.
- Heavy rain and cold weather also suppress mite numbers.
- Broadleaf weeds like mallow, bindweed, white clover, and knotweed enhance mite numbers.
- Suppression of these weeds with cultivation or grasses may reduce mite numbers.
- Mites may be washed from the tree with a strong stream of water.
- Water trees properly, as...