May River Bluff "Holey Hickory" Here is the evidence of the insect activity on the outside of the bark. PreviousThis is the critter, flathead borer larva, that created the gallery of tunnels which gives these bowls their interest and color NextSome borers are active just under the bark. This one riddles the entire tree. Bad for the tree; good for the bowls. Here is the evidence of the insect activity on the outside of the bark. Here is the evidence of the insect activity on the outside of the bark. $0.00 Add To Cart Facebook0 Twitter Pinterest0