Summer squash is Cucurbita pepo, which is very vulnerable to borer. A couple things to try:
1) Plant a parthenocarpic summer squash hybrid (such as Cavili (Territorial Seed, Jungs), Perfect Pick (Jungs) or Partenon (Territorial Seed), which can set fruit without insect pollination.
2) Grow the plants under spun row covers until they are blooming.
3) When you take the row cover off, wrap the stems in nylon hose material from ground level to around 8-10 inches above the ground, which is supposed to keep the borer moth from laying eggs on the stem (usually laid close to the ground).
4) Planting more hills of squash (and growing them under the spun row cover) every 3 weeks may allow you to get a brief harvest from each one before they succumb, but that would extend it hopefully past the egg laying date.

Two other options: 1. Try a C. Moschata. They are all actually winter squash, but several are used as summer squash. Climbing Zucchini/Tromboncino/ Trombocino/ Zucchetta Rampicante/ Italian Trombone Squash is the most popular. 2. Lagenaria siceraria, most popular is the Italian Edible Gourd/ Italian Squash/ Tasmania Bean/ Zucchetta Cucuzzi/Serpent of Sicily/ 'Cucuzzi'

Thanks. The parthenocarpic idea under cover sounds good if I can get the seed at a reasonable price. Since they get clobbered just after I pick the first couple squash I doubt that covering them until bloom would do any good.

Alas, there's no such thing as "past the egg-laying date" since there is another wave of borers in August -- just in time to wipe out the second planting that I put in just after the first wave subsides -- again just as I pick the first couple squash.

I'll look into the cucuzzi too since I've got more than enough moshatas in the winter squash bed.

I was able to find a parthenocarpic zucchini -- Perfect Pick -- from Jung Seeds so I'll try a two-pronged approach. The Perfect Pick under row cover (good source to get very lightweight cover CHEAP?), and the rapid maturers -- Eight Ball and Horn of Plenty -- out in the open in the hopes of getting a reasonable crop before they are killed.

I'll probably plant a few hills of my beloved white patty pans too even though I know I'll only get a few squash before they die. They're my absolute favorite grilling squash.

What do people think of this one? It's $20.95 for 50 feet. I've been thinking of using something like this for isolating tomato plants.

Also, we don't have SVB (yet!), so I've no first-hand experience, but does wrapping the stems with aluminum foil ever work?

Here is a link that might be useful: Agribon+ AG-15 Insect Barrier - 118

Oh, I meant to say, too, it seems George mentioned growing Scarchuk's Supreme acorn squash for its SVB resistance. I understand a number of people use it as a summer squash.

Here is a link that might be useful: Sand Hill Squash Varieties

I wouldn't say that aluminum foil around the stems never works. But I haven't been successful with it in this particular situation. The borer holes appear well up on the stalks, on the leaf petioles, and sometimes even in the squash themselves.

The reflective mulch DID seem to help with the squash bugs (though not as much as telling the 9yo to squash all the eggs he could find does).

You might also try keeping the plants under cover and hand pollinate.

I have a question about the a parthenocarpic summer squash..... if they can set fruit without insect pollination why not keep the covers on them all season? Why take the covers off and have to put foil on the stems if they will produce under covers without insect pollination?

iam3killerbs,

You mentioned that "Since they get clobbered just after I pick the first couple squash I doubt that covering them until bloom would do any good." You've experienced that because they had been laying eggs probably when the plants were small and had been developing unnoticed for a while, so when the plants start productions coincides to when the borers are big enough to kill the plant. Cover are to get a good head-start. Keep in mind it takes 7 days for the eggs to hatch and they eat and grow for 3 weeks, so I think you have a good 2-3 weeks of production before you start noticing the plants suffering. The idea is to remove the covers for the first female flowers, not the males which come earlier. I just removed mine since my crook-neck got too big, but I had been hand-pollinating a few and have already gotten 7 squash from the three plants even before I removed the covers.