I have what some people have told me is a Hackberry tree in our backyard. It seems to have a problem with some kind of insect raising bumps all over the leaves and the tree is also losing leaves. I noticed this a few years ago and have fertilized it over the last two years which I thought was helping. However, this year the problem seems to be worse. How can I get the problem identified and learn what I can do to help the tree? This is a large older tree that is our main shade tree for the house.