j, I strongly recommend traps as they serve several useful purposes. Obviously, catching beetles in the trap is one. A second advantage is that you'll be able to hit a lot of the beetles with your sprayer as they hover and cluster around the traps. Third, you can use the traps to lure the bugs out of the trees, so you don't have to spray them. Once I had the traps in place, the damage to our trees was minor. Unless you examine the leaves on the trees closely, you wouldn't be able to notice any damage at all.
BTW, the gloriosa lilies are up!
