I am seeing small, light green, flat splotches on my pear, peach, lilac and Japanese maple trees. The lilacs got them last year and this year many of the stalks were dead. I removed them all and started looking closer at the other trees. The splotches don't look like the pictures of lichen, they are smooth and flat like the bark itself is discolored. Please help, I have a lot of trees and have to try to stop this.