squash vine borers

[The Finisher.66]

About time to get proactive on these ruthless pests. Havent seen any in mine yet, but I'm ready!

https://www.extension.umn.edu/garden/ins ... ne-borers/

[rainbowgardener]

So what are you doing pro-actively. Squash vine borers are the worst pest in my garden. Nothing else destroys a big, beautiful fruiting plant as quickly and totally. I just gave up on growing zucchini, due to them.

[The Finisher.66]

Liberal use of seven dust at the base/crown of the stem, and a nylon stocking draped over it as well. Prevents the moths from laying eggs. I also keep an eye, and ear out for them. Catch and kill. We can only do, what we can do. They start early here in Lexington, SC The beginning of May, actually. Too much maintenance though. This will probably be my last year also.

[rainbowgardener]

I'm not willing to use the Sevin:

Human toxicity: Carbaryl (active ingredient in Sevin) can produce adverse effects in humans by skin contact, inhalation or ingestion. Athough, it may cause minor skin and eye irritation, carbaryl does not appear to be a significant chronic health risk to humans at or below occupational levels. In humans, acute effects of carbaryl exposure include headaches, nausea, incoordination, and difficulty breathing. Carbaryl can cause a variety of behavioral effects, some of which are relatively long-term. It also suppresses several functions of the immune system. Exposure to carbaryl has been associated with a higher incidence of the cancer non-Hodgkin's lymphoma in farmers and brain cancer in children

Animal toxicity: Carbaryl is acutely toxic to fish. Carbaryl is acutely toxic to birds, although the dose required to kill most species is greater than that required to kill mammals, fish or insects. Carbaryl also adversely affects birds at lower doses by reducing the population of insects and aquatic invertebrates that the birds feed on. Unhatched and young birds appear to be particularly sensitive to carbaryl exposure. Earthworms are sensitive to small amounts of carbaryl in soil. In field studies, carbaryl treatment reduced earthworm populations by between 50 and 90 percent. Follow-up studies showed that populations took five to twelve months to recover and that the rate at which mineral soil was incorporated into thatch was significantly impaired during this period. It is toxic to frogs, shrimp, crabs, clams, snails, some aquatic insects, and many pond living creatures. Carbaryl is highly toxic to honey bees, certain beneficial insects such as lady beetles, and parasitic wasps and bees.

Plants: While insecticides are not usually assumed to have adverse effects on plants, carbaryl's use as a plant growth regulator (chemical thinning agent) makes effects on other plants unsurprising. It has been shown to decrease germination success, inhibit seedling growth, reduce photosynthesis, and reduce nitrogen fixation. Note that several different people have written in to helpfulgardener to say that their gardens died after being sprayed with Sevin.

Fate in the environment: Because of its chemical characteristics, the U.S. Environmental Protection Agency (EPA) identified carbaryl as one of the pesticides with most potential to leach into groundwater. It has been found in groundwater in California, Missouri, New York, Rhode Island, Virginia, and Wisconsin. Carbaryl was the most commonly detected carbamate insecticide in the 1991 U.S. Food and Drug Administration pesticide residue monitoring program; it was the tenth most commonly detected pesticide. It was also one of eight pesticides detected in baby food samples . It has been banned in United Kingdom, Denmark, Australia, Germany, Sweden, Iran and Angola and other places. See https://www.helpfulgardener.com/forum/vi ... 11&t=57653 for references.

And even if you are willing to use it, not sure how well it will work. The trouble with the borers is the adult flies in, lays her eggs at the base of the stem. She may or may not be bothered by the residual insecticide there, since she doesn't crawl over it and doesn't ingest any or stay long. But even if it kills her after she lays the eggs , that doesn't matter. She was probably going to die soon anyway. So then the question is will the residual insecticide harm the eggs? I don't know the answer, but eggs are inside the shell and are a lot harder to kill than bugs. Then the eggs hatch into larvae which drill into the stem. So is residual insecticide going to kill the larvae while they drill through it? Again I don't know, but it is a brief window of opportunity. After that, they are inside and nothing you do to the outside will matter much.

I have tried keeping the base of the stem covered with soil; that did not save my plants. They say you can spray the stem with kaolin clay which acts as a protective barrier. I have not tried that. As I said, I just gave up - too heart breaking to have a big beautiful plant produce the first zucchini or two and then just collapse and die. I know other gardeners here in town who have also given up on them.

[pepperhead212]

SVBs have also been a bane to me in my garden, making it impossible to grow non-moschata squash. I have tried countless tricks touted to keep them away, but nothing works. The only thing that will really work is a systemic insecticide, but who would use something like that, even if we could get it? Makes me wonder what might be in squash in the stores, unless it's organic.

[PaulF]

In the past I have used Sevin to kill squash borers, but because of danger to pollinators I have drastically reduced its use. A very bad infestation will see me still using chemicals. For me, in my relatively small garden (50'X50'), diligent clean-up program at the end of the year along with getting down on hands and knees looking for eggs on the underside of leaves and hand removing all I can is the best solution. The dirty devils show up but in reduced numbers most years. This year being cool and wet here may be conducive to borers. I use Sevin as a last resort.

[The Finisher.66]

Sorry to disagree on the Sevin dust, but pollinators arent attracted to the ground, and that's where I use it most, and it is so little, it has no bearing whatsoever on the environment. Not like were crop dusting a thousand acres here!....LOL

I guess a little Sevin dust prevention isnt worth the life of a beautiful, WILL to live plant?

[The Finisher.66]

Also the Sevin dust is consumed when the larvae hatch and start there journey within the vine, which then kills them. this has nothing to do with mother laying the eggs. Seems to work fine fo me.

[applestar]

Last year, I grew some susceptible squash under a protective tunnel made with "garden quilt" -- a heavyweight spun bonded fabric. These were pepos and maximas. As a comparison, I also grew some outside the tunnel, as well as moschata and mixta squash which are described as SVB resistant (solid stems).

I had to increase the size of the tunnel (actually initially they were planted under a commercial "insect barrier tunnel" made with nylon netting) during their growth, and it was a bit of a chore to open the tunnel and hand pollinate, but the ones under the tunnel were never infested.

The unprotected maximas and pepos outside the tunnel DID become infested, but I attempted to slow their progress by injecting the stems with Bt (Thuricide) -- and I was able to harvest.

These were winter squash and I harvested some of the earliest set fruits after they had matured and some later set fruits while still immature due to SVB's reaching the fruit stems and in one or two cases, all the way inside the fruits. Eventually ALL of the unprotected maximas and pepo vines went down due to SVB in the classic sudden wilt.

None of the resistant mixta and moschata varieties were infested, though in a previous experiment, Tromboncino did become infested later in the season on branch vines.

A problem I encountered with the tunnel was that I missed the maturing of three of the winter squash fruits during a particularly wet and hot period (about 1 week during which I didn't open the tunnel at all) and they became completely moldy. I think this was due to the dense weave of the fabric, and could be avoided if I were to use a proper insect barrier netting with more open weave and air flow. I was more diligent after that and continued to harvest matured fruits though by then I was tired/bored of hand pollinating and had stopped so no additional new fruits developed.

[The Finisher.66]

Interesting methods. I guess If we want something bad enough, we will go through any lengths to get it. A lot of maintenance involved for the things we love. Thank God this is just a hobby for me. I actually give away to friends and family, more than I keep for myself. Thanks for that post though. I guess there is "more than one way to skin a cat"

[gumbo2176]

After several attempts at growing zucchini and yellow crook necks only to watch the plants whither away mid production, I've decided to not plant them any more. SVB's are horrid pests that are abundant in my part of the world I'm sorry to say.

I did the tunnel method last year but it has its drawbacks with having to pollinate the flowers by hand and I got a good bit of fruit from them. However, I went out of town for several days and while gone the wind apparently got strong enough to take the cover off the plot and that's all it took for the borers to take control.

The cost of summer squash at stores this time of year pretty much make it a no-brainer to simply buy them and not go through all the hassle of trying to fight Mother Nature.

[The Finisher.66]

Spoken like a genius!...LOL We should garden SMARTER, not HARDER, I like to say. I am blessed then, as I have no problems here. Since the moth cocoons are already in the earth, and there is nothing we can do about it, weve probably turned the earth over, right on top of them to plant our stock, so they don't have to go far. I sprayed my freshly tilled, garden area with "Malathion" liberally to kill the cocoons, and other non welcomes, and then waited 2 days before implementing sowing. So far it has served me well. I would be freaking out if I had yall's problem. They must be pretty persistent in certain zones.

[Taiji]

Only one time did I ever have trouble like that with zucchini a few years ago. The plants would start to wilt, I didn't know what was happening. I would water more heavily and they would perk up for a while, then wilt down again and finally give up the ghost. I know now it must have been the vine borer. I just kept replanting seeds until finally some plants made it. It was probably after the life cycle of the borer had passed. This was the only time that ever happened with me. I couldn't understand it, I always thought zucchini was pretty much bullet proof. Will see what happens this year, just put in zucchini seeds a few days ago!

I have heard of some people having trouble with the vine borer around here with butternut squash though.

[applestar]

I think in warmer regions with no freeze to control them, you also get melonworms and pickleworms to contend with.

This year's rotation has cycled back to massive solanacea -- tomatoes, peppers, potatoes, eggplants -- planting, so I have no time or room for the protective tunnel technique.

My hopeful strategy for pepos and maximas this year is to plant extra early using the pre-germinating and other techniques, plant many (trying to using up some of the oldest summer squash seeds) and see how (if) many can outrun the SVB's and give me some harvest before getting overwhelmed. -- flower buds are starting to develop now.

I am also growing Tromboncino again to harvest immature and use strictly as summer squash. I was also going to try Cuccuza (a type of gourd also harvested immature and eaten like summer squash after peeling), but so far I haven't been able to get the seeds to germinate, so I may have to push this particular type to next year's experiment. If all goes well, I should have some immature luffa to try though....

I'm growing two kinds of other moschatas and one mixta for winter squash.

[Breanna.link]

posted but again

[imafan26]

So far I have been lucky. I have not encountered squash vine borers yet. Pickle worms and other boring pests that bore into pumpkin fruit yes. The pickle worms are few and they tend to kill young fruit so they are easily picked off and tossed, whatever bores into my pumpkins only get about 1/4 deep and if the pumpkin is big enough it does not kill it so it is still edible. The biggest problems for me are still fungal diseases and the rampant vines climbing over my trees and trying to escape the yard.

[The Finisher.66]

It seems as if we just take our chances, and see what happens.