I not sure if this is the right place to post this but here goes. I live in N.J. and I have several Oaks, I guess white Oaks??. Well anyway there are these hard black cocoon like balls growing on the branches, some small and some bigger. I notice them when the leaves fall off in the winter. Well anyway I saw a tree tonight in a park a few miles from home with the same problem, but worse. The Oak was completely covered in these things and the were much bigger. They actually looked like dog turds on the branches, not to be gross, but that's what it looked like. I looked at these things a bit closer and they are as hard as a rock and they have small pin holes in them, like something grew inside and then borrowed out. Anyone know what these things are?? Insects, Beatles or disease. I would like to save the trees if there is a problem, but I have been contemplating cutting them down and replacing them with Bradford Pears. If there is a major disease with the trees, this could help me make a decision.