One of our Live Oak's leaves, at the very top, turned red, then yellow. An arborist said "new growth". Well, they've stayed a greenish yellow. Some ends of branches have defoliated. Now, the leaves on the lower branches are randomly turning red, then yellow. It is NOT new growth. Last month, the entire tree had black spot under all its leaves.

Now I notice certain Live Oaks in this whole area of Dallas have this.What is it? Is my tree going to defoliate? In March, an occasional small green caterpillar hung from a single strand. But very few. Help!!!