Garden Pests and Diseases: Brown/Red Spotting or Burning on Maple Leaves, 1 by Wazatron

Wazatron wrote:
Hello all! I\'ve tried to research this one but it\'s a tricky one to find the right keywords to avoid pulling in all sorts of results that are obviously not relevant. Anyhow - I have a very small maple tree that I\'ve been trying to grow from a seedling found in my yard. It was growing very well, and took to up-potting last year nicely. This year it grew nicely through spring and then sort of halted. Over the past few months the leaves have gotten sort of a rust brown/red scale on them. They\'re not bumps like gall mites produce, and they don\'t look like brown leaf scorching. I don\'t see any obvious signs of pests, but perhaps I\'m missing them?

I\'m at a loss here and hoping to get some thoughts and advice. Thank you!