Answer: The spikes you've noticed on the leaves of your tree are the result of maple bladder gall mites. These little insects feed on the surface of leaves in the spring and leave reddish colored bumps which grow throughout the season and later turn brown or black. The insects feed in the spring, which is when they are susceptible to control. This kind of damage may look unsightly, but it won't hurt your tree, and control isn't generally necessary.
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