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Brown Leaves on Birch |
Question:
We have birch trees in our front yard and many of the leaves are turning brown. We saw that there were a few caterpillars (brown) on the tree. None of the leaves had holes in them. All the neighbor's trees have this problem too! The leaves are falling like it is autumn!
Minnesota Master Gardeners say:
Your birch tree probably has leaf miner, a common insect on white and gray birch. As the leaves were forming, a wasp deposited single eggs in a slit in the leaves. When the larvae hatched, it feeds in between the layers of the leaf. After it finishes eating, the leaf will turn brown and drop. New green leaves will replace the dead ones on the trees and the feeding may be over. Check this U of M publication for more information:
http://www.extension.umn.edu/info-u/environment/BD553.html
Here's more information from Wisconsin:
http://www.entomology.wisc.edu/ppbirch.html