Sorry to say it sounds like squash vine borers. I stopped growing zucchini because of them. I didn't know they attacked corn, too.

Some people recommend cutting open the vine and removing the worm, but I didn't want to go that route. I figured if the worm was already there, the damage was probably done. Maybe they would have better suggestions for you on the Veggie Forum.

Next year, when you plant your zucchini seeds or plants, sprinkle garlic powder on the soil. This hint was given to me years ago and it's always worked. I'm sorry about this year's crop!

The thing is they dont look like SVB's to me....I've spent the better part of the last 2 days out there looking and have not seen any of those evil looking moths....and when I cut open the stalk, what I see does NOT look like a grub, it looks more like a translucent termite or ant-type larvae...1/4 of an inch long..and any bad spots are brown mushy areas , with a tan/brown mushy looking excrement near them...i also have tons of ants in the garden, and all around the corn stalks...plus I never heard of SVB's attacking corn either...and these are definitely them same critters, as the autopsy proved.. Does anyone have any $%^&^$##-ing idea what the hell is going on?