Last week 3 of my pumpkin plants were killed by the vine borer. I slit the stem and sure enough the ugly white grub looking insect was inside. As usual you don't know you have it, until the damage is done and the plant starts to die. I have had very limited success by cutting the worm out and having the plant live but most times not. After googling and reading about this nasty little pest, I found a site that said panty hose wrapped around the stem at the base could be effective in not allowing the larvae to penetrate.
Not having a pair of panty house, I resourcefully used coban. It actually worked great since after you wrap it, it will self seal closed. Took me about 30 mins to cut strips and apply it. So far so good.
Coban comes in pretty flourescent colors and I only had pink and orange. Looks funny, but I hope it will work!