Same here, I've seen many trees with the tips of branches turning brown. If you look closely, you can actually see the notches along the branch where eggs were laid. Not sure which they "favored" for laying eggs, but I've seen the tree flagging on oaks, dogwoods, sweetgum, and maples in particular. Probably some others, too. And even some shrubs and bushes. Supposedly it's good for the trees, like a "natural pruning"...as long as it's not too young or small of a tree (which could cause serious damage, I've seen where people actually fastened a net around their small trees!). That, and apparently all the holes left in the ground from where they came out aerates the soil. I guess this current generation is now "back to nature"!!