I'll still vote for SVB's. Did you check the base of it very throughly?

Could also be squash bug. The new hatchlings carry a wilt that kills the plant.

I went back out yesterday and all I saw was the SVB, none of these other ones. This other one was a distinctive diamond shape, didn't think the borers came in that shape. They were also about 3X the size of the borers. I didn't remember til later that the neighbour uses beneficials (a large market garden operation). We get them in our garden sometimes. Could this be a beneficial? Marg

Squash Vine Borers are little white larvae worms up to an inch long with two little black dots that look like eyes.