Hi Lynette! Welcome to ATP and to our Iris forum.
I'm sorry to hear that you have borers. I had them too when we lived in Elmhurst, and my cousin has them almost every year in Arlington Hts. I think that part of the country is very susceptible to them. Your best defense is to keep a sharp eye out for them and catch them early, regardless of which method or product you use. Good luck with that.
So -- where in northern Illinois are you?
