You need to contact your County Extension office (USDA Extention is probably how it would be listed in the phone book). Ask them WHERE you should go for advice.
You aren’t telling us if this is Sweetcorn or #2. And given that more and more Sweetcorn is white or Bi-colored, it is difficult for those of use who ‘know corn’ to be able to assist you given the information you’re providing.
Call the Extention Office,, they can guide you to the proper authority for your area.
“They attacked the sweet yellow corn more then the white corn.”