Have oak wilt on my land and neighboring state land. Trees will be fine and within 3 weeks turn brown and drop their leaves. DNR has a 7 foot blade like root cutter on a dozer. Trying to slow it by cutting root system of affected areas. You must cut roots touching affected trees as stated above, chemical treating by tapping root base is too expensive for number of trees I have and treating must be repeated. They recommend not cutting or pruning trees until after July 15th, later the better. Damaging trees is a way of spreading by insects. I lost 9 last year and have 4 bare trees now. Problem here is Gypsy moths are back and stressing trees. Red oaks are most affected and white oaks are more resistant to wilt. I will start cutting around September. Kind of sickening to watch.