This article suggests beneficial Nematodes injected into the vine, but doesn't say what those are. It also suggests to slit the vine with a razor as soon as you see a hole, and get the caterpillar out, then cover the vine back up.
also this is interesting, but would be time consuming on a large scale. "Or just wipe the stems every five days vigorously with a damp cloth and wipe away the eggs. An Auburn University researcher found this tip in a farming book from the 1890’s, when even now-ancient remedies like BT were still half a century in the future! Wiping with BTK or insecticidal soap should be even better. "
http://www.gardensalive.com/ar...
here's a pdf that suggests the slitting of vines too, but also mentions placing a board for them to congregate on, then squishing.
"A method in use to control squash vine
borer is syringe injection of the bacterial
insecticide Bt (Bacillus thuringiensis) into
each vine by hand. In home gardens or
small market gardens, growers often try
to control squash bugs by hand picking
or placing wooden boards near the plants,
where squash bugs will congregate for hand
collection and disposal. For squash vine
borer, small growers are advised to slit
each vine showing frass (the insect excrement)
and extract the larva before the vine
is irreparably damaged. Such methods
are not suitable for commercial production
of three or four acres because of the hand
labor involved."
https://attra.ncat.org/attra-p...
