Tentiform leafminer
Phyllonorycter blancardella
14 host plants
Last updated
Tentiform leafminers create distinctive, grayish, tent-like folds in apple leaves and other hosts, with larvae feeding inside the mine. Initial mining appears as a small bump on the leaf surface. Folded leaves become visible by midsummer. Heavy infestations can cause leaf yellowing and premature drop, primarily affecting landscape crabapples and Serviceberry.
This is predominantly a cosmetic concern for ornamental trees. Prune off infested leaves in early summer to reduce pest numbers and improve appearance. Do not spray, as leafminer parasitoids (including Eulophid and Pteromalid wasps) are disrupted by pesticides and naturally suppress infestations. Maintain tree vigor to support rapid foliage replacement.
Quick Reference
Adult moths are about 0.12 inch in length. Wings are held roof-like over the body and are golden bronze with white bands. The larvae vary in appearance depending on their age, as they progress through five instars. Young larvae are legless and cream-colored. Older instars have legs and are cylindrical in shape, cream-colored and about 0.125 inch in length. Mature larvae are yellow and about 0.167 inch in length. The larvae feed within the leaf tissue creating dead discolored areas on leaves. If...
Cultural Controls
- Pinching mines when first seen (on dwarf varieties) can help suppress later generations.
- If mines average 2 or fewer per leaf – expect no serious impact to tree or fruit production.
- Rake fallen leaves and dispose of them in the trash.
- Do not compost or bury leaf debris from infested trees.