Question
QUESTION: Hello,

I have what I believe is a Autumn Glory Maple Tree.  Different leaves on the same tree show two different symptoms.  On some leaves, I see small, red raised bumps over the leaves.  On other leaves, I see slightly larger, brown, flat spots.  I have photos of both symptoms if that would help.

Do you know what these diseases are, and should I be worried about the health of the trees in either case?

Thanks!

ANSWER: These are leaf spots caused by a tiny gall wasp. They will not cause any real health problems with the tree. Aesthetically they may make the tree look bad and may cause the leaves to drop pre maturely. The insect lays its eggs on the leaf and secretes a chemical that causes the leaf to grow over the egg. The egg hatches and does not further damage to the tree. Spraying with insecticides would take timing the spray with the wasp laying eggs --not a easy thing. And not really needed since the damage is very very small. I would not worry about these spots.

---------- FOLLOW-UP ----------

QUESTION: Thanks for the quick answer!  Are the gall wasps responsible for both the smaller red bumps and the slightly larger brown flat spots?

Answer
They could be but the brown spots could be a leaf fungi spot. Leaf spots from fungi are not a problem that involves the health of the tree. As in the gall wasp the worst thing would be the leaves might drop prematurely in the fall. Leaf spots from fungi are not normally treated since it would take a fungicide spray used as the leaves budded out and re applied after each rain. Not worth the effort. I would not worry about either spot.