I did have foil under a couple of the plants, and from what I can tell they have not been bored yet, but I will not get my hopes up as the larva are clearly just getting started. I stuck pins through the bases of the plants with the tell tale "saw dust" at the openings. The plastic mulch over the bed doesn't allow for any mid-vine root formation. Double edged-sword as it seems to be the thing that has allowed these plants to mature in a timely manner.
So, to sum it all up I have a garden suffering from Late Blight and Squash Vine Borers, and it has mainly gone undiscovered and untreated due to neglect. My days have been filled with too much running around, beach going, and hiding from the heat of the sun, and not enough time spent peering closely at every plant watching for any sign of pest and disease that has settled in. And of course the morning was spent dealing with the borers instead of spraying the tomatoes, so now they will go another day with out protection from flying blight spores. If I don't spray them tonight someone please come through cyberspace and slap me OK?