Could you list the specific things you've tried? Physical barriers around squash stems? BT on the surface? BT injections if the plant gets infected? Harsher insecticides? Monitoring for eggs?

If the moth can't lay the eggs on the plant then the larvae can't get to the plant and kill it. They may be devi-spawn but they aren't cabable of teleportation. ;)

Physical pest barriers work but they have to be done right - right material, well tucked in and under, secured, applied early and maintained, not just draped over the plant. And you have to hand pollinate. Timing the plantings to avoid moth cycles also helps but you have to really know the pest cycle times in your garden - for me that is 2nd and 3rd week in June and has been for years now. Plant early for early fruit set and then plant after.

Dave

Hi! In another post somewhere I mentioned how I've successfully used the method of slitting the stem and removing the little borers before they do major damage. I've done this for a number of years. I agree with Dave that knowing when they are going to appear is vital to controling the damage! If you're interested, this should link to that discussion. It was pretty detailed, and I think someone posted some helpful pictures too... Best of luck!

Sunni

Here is a link that might be useful: SVB discussion

sunnibel, I've done the exact same thing as well. If you do it before the plant is too weakened from the infestation you have a better chance. Where's a wilted leaf, check the crook where the stem meets the vine. If you see something like sawdust, that's where the larvae entered and where the grub is lying inside the hollow vine. I make a slight slit, take out the grub then gently bury that part of the vine and water it well. Most times it works.

It's funny. As far as garden bugs and pests of all kinds, I'm not squeamish. Even the loathsome tomato hornworm.
This is the exception. Some of those grubs can be as big as your little finger. Be forewarned!

Jackinthecountry

You just totally grossed me out. If I see signs of svb l have to make hubby extract that grub

Ha ha! Yes they are a little more on the squishy, ugly side of things aren't they? The adults are almost pretty, though. Remind me a little of a hummingbird moth. If they just ate a few leaves like the swallowtail 'pillars do on the dill I would probably just leave them to it! (I always feel sorry for the tomato hornworms because they turn into amazing moths but I doubt most gardeners care.)

I'll qualify my earlier post by saying that I like the stem slitting method because it doesn't cost anything, but it would probably not be practical on a large scale. So I suppose if you had many plants, I would go for the row cover. They really do only show up for about a week or so and that's it. Cheers!

Sunni

Last year I had read that to wait until the threat was over, which meant plant in July,and it seemed appropriate. So, thus it went and no borers. Also (and this seemed strange) a contributor insisted that a couple of garlic cloves, cut up and placed around the squash plants, would discourage the moth. Ok, that's what I did. Still no borers. Very little cost there and got some nice summer squash.

Does anyone know the steps that take place for the SVB to do it's damage? ie: moth lays eggs on underside of leaves, eggs hatch, but where to they enter the plant? from the stem of the leaf that they are laid on?

Or do they migrate down the stem of the leaf they are on and enter into the main stem of the plant?

The reason for asking is I had an idea for a barrier that might work...I was thinking of a material that is put around the trunks or trees for ant control. It's a sticky thick gum like material that comes in a tube. If I knew that the larve migrate down the plant, then theoretically you could use something like this everywhere there are leaf junctures? Would it deter them? Maybe something like a vaseline based material that they could not move through?

any comments on how this could work?

AFAIK, they're laid on the stem, not a leaf.

Rjinga, I'm not sure if it was just a bumper crop of SVBs last year here in Austin but they managed to lay eggs all over my poor little patty pan squash plant (leaves, stems, main stem). Here are some pictures of 1 small squash plant I pulled last year, the brownish red dots are SVB eggs.

http://i334.photobucket.com/albums/m413/Johnny_Lee_3/gardenjuly08041.jpg

http://i334.photobucket.com/albums/m413/Johnny_Lee_3/gardenjuly08048.jpg

They enter the plant from the first hollow portion of the plant they come across or directly into the main stem. If the egg is laid on a hollow portion of a leaf stem they bore right there, if on a leaf they make their way to the nearest leaf/stem junction and bore there. Once inside the leaf stem they chew their way down till they get to the main stem. So to be 100% effective you would likely have to apply the goop to the main stem and every inch of the other stems. Hope the info helps and good luck.

I'm growing some trombocino squash this year because they say it is SVB resistant but I'm not holding my breath.

I'm in the sixth year of squash cultivation just south of Houston. Squash borers found my yard in the third year of gardening. At first I ignored them (at my peril), then I tried picking eggs off (never picked all of them), then I tried parthenocarpic squash and row covers (borers got under the row covers).

Then I got ambitious. I decided to practice a combination method this year. I'm growing the following:
Zucchini Black Beauty
Zucchini Cocozelle di Napoli
Early Prolific Yellow Straightneck
Yellow Crookneck
Lemon Squash
Woods Prolific Bush Scallop
Blue Hubbard
Thai 'Rai Kaw Tok' pumpkin

Blue Hubbard was originally intended as a sacrificial lamb to attract squash borers and distract them from other squashes. Next thing I knew, the two plants were taking a lot of real estate and making squashes and that's when I decided to grow them long enough to get squashes off of them.

My strategy is this:
1. scout for eggs every two or three days and remove eggs you find.
2. Encourage rooting of Blue hubbard by burying parts of vines.
3. Inject stems with Thuricide solution weekly.
4. Spray stems with Rotenone solution weekly.
5. In case of suspected borer entry, inject the entry channel with BT solution or cut the borer out.
6. Attempt to kill females that show up to lay eggs. This only worked once but very satisfying. Not recommended.

All this is more work than I have bargained for, but so far it seems to be working. I've noticed the first eggs on April 29th on a zucchini and I have only lost one plant so far. I noticed infestation on it in the first week of control, which suggests to me that the plant was infested before I started control. I occasionally see a small entry hole on the Blue Hubbard with a bit of frass coming out, but the larva appears to be dead due to ingestion of rotenone. I have removed five larvae to date, mostly in the second and third weeks of control. I removed part of a small secondary vine on Blue Hubbard yesterday. I've lost two developing Blue Hubbard squashes, too.

I'm enjoying an avalanche of squash and I'm looking forward to three Blue Hubbard squashes in a few weeks. They will be on the small side, but still... Thai pumpkin is exceptionally resilient to pest and disease and it is making several green pumpkins in the 3-6 pound range. In general, vegetables bred in tropical parts of Asia do very well in my garden in the summer.

I've been looking around for some data on SVB generations in coastal Texas, but have found nothing so far, so my scouting also attempts to answer the question about number of generations per year here and whether they overlap or not.

SVB may be a devil incarnate, but I'm doing my best on the exorcisms. Methinks there is salvation.

Has anyone considered doing some kind of completely enclosed area surrounding the squash using netting or mesh making kind of a "GH" or tent? Couldnt one harness some bees who could move into the "dome" for the pollination party? Can you create a home for bees so that they would stay in one place?

Clearly I've failed at ridding my squash of the SVB, so I"m just thinking of options.

I'm so glad someone started this thread; I was just thinking about SVB/SB control this morning (and to my way of thinking, BOTH kinds of bugs are Satan's Spawn!) Does planting marigolds around the plants have any effect? When the seedlings put out the first set of true leaves, we sprayed Sevin spray at the base of every plant but now that the blossoms are coming on, of course I don't want to use poisons. I am trying to keep an eye out for eggs on stems, but I have Vertigo which makes turning upside down to look at the underside of leaves not a real fun thing to do. So I am thinking of doing a major marigold planting if it will work at all.
Thanks!
Edie

Marigolds do not work. I planted the French Marigolds in my winter squash raised bed. My Red Kuri plants were beautiful with several nice size squash just beginning to turn orange. A few days ago I went to hook up the soaker hose and 3 of 4 plants were in total collapse. I could not find the entrance made by the borer. My winter squash grows on tall trellis so row covers are not an option for me. Somehow - some way in 2010 I am going to make a bomb proof cover for a raised squash bed. I saw one on Gardener's Supply website. Link below. Perhpas I will just grow Seminole squash because the SVB can't get into that stem.

I totally HATE this bug!!!

BTW in my area we have 2 SVB seasons. They come in July and then again in August.

DL

Here is a link that might be useful: Pest Control Net for raised beds

Kasiaw wrote: "3. Inject stems with Thuricide solution weekly."

Is that full strength or diluted? I want to start injecting as a preventive measure...anyone know? I am one who has an August hatching as well as June :-(

It was suggested to me to put some pantyhose around the stem so the buggers couldn't bore their way in. It's worth a shot for me next year.

dancinglemons - that website shows the net for their 3 by 3 bed. I have a couple of those beds and believe me, one squash plant is going to much more than hang over the sides of that puppy. You will never get a snug net on that thing with a full-grown squash in it unless you severely trim it down. Nice idea - but needs to be MUCH larger for squash. And you will have to pollinate them yourself.

raisemybeds,

Oh yes!! I just use it for illustration of what someone can do. My DH is making an enclosed 'house' from mosquito netting for our 2010 growing season. It will be sort of a hoop house but made from mosquito netting not thick plastic sheeting. The idea came from that Gardner's Supply product and from his having been military during the Vietnam era. We are going to try it and will hand pollinate the plants.

DL