Around here, the only thing I can offer is that when the worms come, and they will come, be prepared to kill lots of them. Feed them lots of food. They will re-generate leaves after the worms clear. Unfortunately, only the worst of chemicals works on them, so it is a tough choice. Spray or hand pick. Fortunately, this year, the Winter Moths are at a minimum, so I will just keep feeding them and hand pick. Yuck!