- Leafminers feed on leaf tissue between the upper and lower surfaces of a leaf.
- They may be the immature stages of moths (caterpillars), beetles, flies, or sawflies.
- Most cause little damage. Several are pests of shade trees. These include the holly leafminers, locust leafminer.
- Birch leafminer rarely attacks black, yellow, or river birch (the birch commonly planted in Maryland).
- Oak blotch leafminer (native moth) attacks scrub, post, black, red and white oaks.
- The larvae (caterpillars) feed just below the upper surface of the leaf, causing irregular brown blotch mines.
- These are minor pests and control is usually unnecessary.