QuestionI have a young autumn blaze maple with thousands of raised red spots covering the leaves. They are about 1/16 inch in diameter, cluster at the base of the leaf & seem to follow the veins outward. Is this a pest, disease, or fungus? If so, is it detrimental to my young maple? I have a second young maple with just a few of these raised red spots, and am concerned for the health of both trees.
AnswerHi Christine:
This may be a gall insect rather than a disease. I am not aware of it having a significant impact on the tree health. Try Google-Images- "Maple bladder gall" insects to look for a match. We usually don't recommend a chemical- just rake up and dispose of leaves.
Steve
