When vines begin to run,apply to bases of plants 4 times at seven day intervals. Pheremone traps for squash vine borer are commercially available. These traps can be used to indicate when moth activity begins. The use of Spintor for looper control will reduce squash vine borer populations. I believe that the eggs hatch 5-7 days depending on daytime temps and humidity

Apply what to the base every seven days?

I've been using Bt and only got one episode of borers so far. They took advantage of a couple days of on and off rain.

I'm glad to report that the surgery and the injection of Bt appears to have worked.