I have a large investment (in my yard) in structures built with treated lumber. Deck, stairway, boardwalk, rose arbor, etc.And the way some of my wood is being gnawed at is starting to frighten me. It seems to start with carpenter bees boring holes. Then some insect gnaws the edges of the holes leaving a real mess. I have bees, wasps and hornets in the area.

Are these insects teaming up to destroy my lumber? Is it something else? I live in Middle Tennessee near Nashville. All of my treated lumber is from the big name-brand hardware store.