I have several Regal Prince oak trees that I'm concerned about. They all have leaves with either holes in them or brown spores on in the inside face; brownish blisters on the outside face (outside face being the face that the sun hits). First off, is this a single issue or multiple issues and secondly, should I seek out some form of treatment for these trees? I looked through the guide on the UMN site and nothing seems to match up to what I am observing.