A few of the squash plants in our garden started wilting for no discernible reason late last week. We lost three sweet meat squash plants before we figure out that vine borers were attacking the squash.
At this point, most of the squash plants have signs of vine borers. The zucchini, spaghetti and acorn squash plants all show signs of vine borers - holes in the base of the vine and wilting leaves. The butternut, Hubbard, and pumpkin plants seem to be unaffected, but I'm not sure if they're resistant or just haven't been hit yet.
Is there anything that can be done for the plants that are already affected? I tried cutting open some of the stems lengthwise and pulling the vine borers out, but I'm afraid I did too much damage to the plants, and I know I didn't get all of the larvae out.
What about the plants that don't show signs yet? Should I wrap the stems in foil?
Side note: We're trying to do everything organically. So far we've been spraying weekly with neem oil, and occasionally spreading diatomaceous earth.