Locust Leaf Miner: Yellow Spotted Leaves on Young Trees

Three young locust trees (planted last September) show yellow leaves with brown freckles. Neighbors lost trees rapidly. The cause is likely locust leaf miner.

Identification

Larvae mine inside leaves, creating blisters that turn brown. Heavy infestation makes trees look scorched. Adults skeletonize leaves in late summer.

Control

• Systemic insecticides (imidacloprid soil drench—Bayer Advanced Tree & Shrub) are most effective because they reach larvae inside leaves.
• Foliar sprays (acephate, bifenthrin) target adults in spring or larvae in early summer.
• Apply according to label; thorough coverage of upper and lower leaf surfaces is critical.

Resource

USDA Forest Service fact sheet: na.fs.fed.us