Jill, I agree that the vining squash have a better survival rate; and C. moschata types (like butternut) are somewhat more resistant to the borers because the stems are solid rather than hollow. And I haven't yet tried it, but supposedly you can inject the vines with Bt to kill the "worms" inside; I bought a "meat injector" syringe a couple of years ago for that purpose, maybe this year I'll give it a try.
The only vining type of summer squash that I know of is the "Zuchetta rampicante" (aka Tromboncino), which can be used as a summer squash when young and as a winter squash when mature (although I found it to be a little coarse in texture as a winter squash). I'm also going to try some yellow sticky traps around the plants this year, which presumably will at least catch an adult or two so I'll know they are present.
