Western tentiform leafminer

Tentiform leafminer larvae create distinctive grayish, tent-like folds in the leaves of flowering plum (Prunus cerasifera) and other stone fruits in western Washington. The larvae feed inside the mine, leaving transparent brown patches visible on both leaf surfaces. Initial damage appears by early June; heavy infestations cause yellowing and leaf drop.

This is a cosmetic pest on landscape trees. Prune off infested leaves by early July to reduce adult emergence and improve tree appearance. Natural parasitoids suppress populations year to year; do not use pesticides. Maintain adequate irrigation and avoid drought stress, which predisposes trees to secondary damage. Most mature trees tolerate leafminer damage with minimal impact on growth.