One of my accounts has a problem with a couple apple trees. For one thing they are finding little green worms (larvae on them). I don't know if they are causing the problem, I have yet to identify them. The problem is that leaves are curling up and dying. They look as though something is sucking the juice out of them. Inside of the curled leaves are webbing and small black particles that look like eggs or either feces. How would I go about identifying this,(website, books, etc.) Any help would be great.