I bought a home at the beginning of the summer in June 2011. It had an already established Weeping Cherry Tree. I noticed about halfway through our drought of a summer, that many leaves had holes in them or brown spots. The past few weeks it has gotten worse. I've read so much about it online and just need some sound advice. It could be the drought and due to lack of sufficient watering that certain insects did not eat other ones. I noticed there were these tiny black insects crawling that appeared at first to be ants. I just bought some fungicide/inseticide and sprayed the tree with it. I have also noticed that early in summer I had scraped the tree with the lawn mower. I avoided thereafter but it had a small knot with sap on it. The wound doesn't look to be completely healed either. So, I have a couple of things going on. Is it the black bugs (which are now gone from spraying), the drought or the wound from the scrape of the lawn mower. I look at pictures of it in late spring and it's dar green and looks great. Now over all the outside branches have a yellow tint to it. The underneath branchs are nice and green with very little leaves with hole or brown spots. I also didn't realize just how fast these trees grow. Any advice would be greatly appreciated. I am attaching a picture late May and pictures taken today as well.