I guess I am learning to have an affinity for Oaks too : ) I will check out the book.
I have become aware of a cycle of bugs and how they interact with the trees. Along with the wasps are black beetles that will try to snatch and eat the inch worms while they are eating the leaves. The inch worms protect themselves by falling on a silken line where the beetles can’t follow, but the dangling worms are easy prey for the wasps. These cycles play out over spans of years with different bugs taking precedence.
Then there are the other plants, underbrush like choke cherries that leaf out much earlier in the year, risking freezes and snow loads to capture the sunlight and moisture before the Oaks leaf out blocking the sun. It seems that each year I notice something new and amazing. Plants seem to live in perpetual warfare.
As I understand it, the moth lays its eggs on the leaves of the oak. The larvae are hatched and fall to the ground. They make their way up the trunk as worms and then feast on the leaves of the oak.
Luckily there's a beneficial bacteria called Bt (Bacillus thuringiensis) that interrupts the digestion of these pests and kills them. I've used Bt to great effect on my trees; I sprinkle a bit around the base of each oak in the spring and it seems to persist in the soil. Google or Amazon would provide plenty of sources for the powder...