Went out this morning and 1 of my purple ash had lost about half it's leaves last night. It's a fairly young one, maybe 5 years old. Looks to be lilac borers. So depressing, hope it makes it through :-(
We're very fortunate in that the Emerald Borer hasn't made it to Colorado yet, The signs are very similar but the ones around here aren't quite as bad. What worries me is the huge overnight loss in leaves :-(
Don't know if there is any consolation in this, but I had an ornamental plum tree, maybe 1.5" diameter and 10 ft tall, completely denuded by japanese beetles last year, and it survived. Every leaf was skeltonized. But the beetles stop eating in August, not sure about the borers. Hang in there, little tree!