Very small insects that get between the upper and lower surfaces of a leaf. They feed on the leaf tissue inside of the leaf, and leave either serpentine "mines" winding throughout the leaf, or brown blotches where the inner leaf tissue has been removed. You may also see small black particles between the leaf tissue, which is the insects' fecal matter, or frass. There may be only a few leaves on a tree or shrub affected, or the entire tree can turn brown if there is a heavy infestation. Oaks, hawthorns and birches are most often attacked by leaf miners. Heavy or repeated infestations may not kill the plant outright, but may make it more susceptible to other problems.
We can be reached at 612.706.8210 for our office and 612.916.1237 for our mobile number if your tree begins to show signs of disease.