Greetings Linda:
In this case, as with most insect and disease questions throughout this forum, I simply cannot make a recommendation without an on-site assessment. Therefore, you will need to contact a professional forester, horticulturist, or a certified arborist to provide an on-site assessment of the tree(s).
With that said, please contact your local U of I county Extension office to see if they have a horticulturist on staff -OR- visit the Illinois Arborist Association Web site for a list of local certified arborists (http://www.illinoisarborist.org/CertifiedArboristsNew.htm).
Best of luck!