Sunday, June 21, 2009

Advice Needed: Squash Vine Borers?

It is time to harvest some of our calabazas, which are in the pumpkin/gourd/winter squash family. About half of them had some damage. Here is the hole in the stem of one of them, wiped free of the sawdust-like frass from some insect. The stem interior was intact (not eaten out) but something got in right there close to the calabaza. In trying to read up on what it might be, the only thing I could find was squash vine borer.

However, here is another fine calabaza, but the hole, which is no larger around than the diameter of a toothpick, is right in the side of the pretty tough shell. Do squash vine borers drill right into tough shells?

Here's a closeup. The brown stuff, I'm guessing, is frass...otherwise known as bug poop.
The calabaza vines are each 50 feet long, and the older parts of the vines do wilt in midday, which I only now read might be further evidence there are borers in there wreaking havoc. However, I 've not seen any evidence on the vines themselves. I've also not seen the moths that are supposed to be present in the daytime, but I do see a lot of wasps, none of them with the red midsections the borers are said to have.
Does anyone know if this is squash vine borer damage for sure? I went ahead and harvested all the calabazas regardless of size since finding the damage, and 4 of the 9 have the holes...all in different places. Only one has the hole in the stem...the others have a single hole, like above, in the shell itself, some right in the side, one in the bottom.
All advice is welcome! I'm not sure what to do. We've thought maybe of cutting the old vine sections and pulling them and disposing of them off-property and seeing how the new vines do....or alternately, of just pulling it all up and hoeing the area to expose the soil to the sun in case there are any bad guys down in there, and replanting with a different type crop.
Help! :)


The Old Gray Egg said...

Just my opinion, here. The damage to the squash looks extremely minor to me. Removing a tablespoon or two of pulp when you go to clean the squash for cooking is a very minor loss, and is far better than trying to make your garden a bug-free zone with the use of pesticides and poisons. Americans accustomed to shopping for blemish-free produce are pretty spoiled. Crop rotation can help if you have a very large garden area, but if the bug is endemic to the area, you should probably learn to live with the little bit of damage unless the plants are being killed outright or your harvest is not adequate for your needs. Don't mean to be preachy here. Just my notions.

Robbyn said...

Egg, thank you for your insights! We're committed to not using poisons, and actually want our bugs to be happy around here...our goal is to shoot for a happy medium...some food for them, some for us. The only reason I'm concerned about the borers is that if that's what this is, they can set up camp in the soil and become a bigger problem later. We'll definately use all the calabazas, we'll just use the damaged ones first. we're hoping for enough undamaged ones to have to store for longer term. We have another vine growing on the property that's about to set fruit, so even if this one needs to go, we'll keep one going somewhere to study what it likes the best. I was just wondering if anyone had any experience with the borers in particular. Any solutions, to us, will have to be chemical-free and pesticide-free...there are too many of the helpful insects around that we really want a balance rather than "pretty" produce :) thanks for your input and feel free to give us your advice anytime!

Melissa said...

It sounds like it could be squash vine borers that reached the plant late in the season. Vine borers lay their eggs on the plant and the larvae tunnel inside - if you find some white grublike critters inside the squash, it's probably them.

duane marcus Facebook me! said...

It most likely is the dreaded squash vine borer. As the Old Gray Egg said the squash will be edible but will not keep long. The adults are usually active in the morning. You can pull some soil over the newer portions of the vines and they will grow roots so if the borer damage in the older parts gets really bad you can usually salvage the plant. Search for the damage to the vines and cut our the larvae. You don't want to let them get to the adult stage. There is a organic pest control product available called Spinosad which is produced from the actinomycete bacteria found in soil and compost. Some studies suggest that spraying it on the vines early in their growth will help control the borers. Spinosad sticks on the vines and leaves and is consumed by the young larvae. It works on other larvae of other pests like bean beetles and cucumber beetles and potato beetles. Also helps against the adults too.You need to reapply it after a rain. We've had success with it recently on the above mentioned pests.

P~ said...

Hey Robbyn! too long since I've posted. Sorry, I read you all the time though!

Hey I checked with the Florida state Extension website and found this listing of pests for Florida vine crops.
A real quick look leads me to belive it may actually be the pickleworm. Squash vine borers actually live in the vine primarily whereas these guys do damage just like what you see in the stem next to the melon, and also burrow into the fruit itself.

This site shows a couple of good images that look like what you might be seeing in the stem end.

I would suggest possibly cutting gone open and looking for the worm. Try contacting your local extension office. They should have a horticulturalist on staff that will look at what you have and tell you what you've got.

You should be able to preserve the ones that have damage by processing and freezing or canning it rather than curing and storing the whole fruit as would normally be done.

Hope this helps a bit.
Best to you!

Chile said...

We had similar damage, in Arizona, to a winter squash developed for this area. It had a huge problem with the squash vine borer, and it did attack the vegetable as well. I just cut the damage out and cooked the remaining parts to freeze.