Protecting Your Squash Plants from Squash Vine Borers

We have 2 nemesis for our summer squash, winter squash and all pumpkins-squash vine borers and squash bugs and they will be here soon if not already here. This post addresses the squash vine borer.

The squash vine borer as seen above has a BLACK AND ORANGE BODY with CLEAR WINGS. If you see a waspy looking bug that is BLACK with ORANGE WINGS, this is NOT the squash vine borer but a tarantula wasp – don’t mess with it as it has a painful bite but usually won’t sting us unless we agitate it and it is harmless to our plants. Take a good look at the picture above so you can identify the squash vine borer.

This video and article, Protecting Your Squash Plants – Vegetable Gardener is from the Vegetable Gardener site (great site) and shows how to protect our squash vines from the squash vine borer.

In addition to using foil and panty hose as shown in the video, I also bury all my stems as they lay down on the soil-main stem and secondaries so the SVB can’t find the stems. Mostly the SVB attacks the BASE of main vine so be sure to protect that part of the squash vine. This use to be an east coast problem but the SVB has finally crossed west of the Rockies. So be on the lookout.

If your plant suddenly wilts even though it has enough water, or if you do see SVB’s around, look for frasse (poop) that looks like sawdust around the base of the stem and that is where the larvae will be-inside the stem eating your plant. You can try to cut vertically (not across) the stem and dig out the larva with a knife, then bury the stem with dirt. Depending on the damage, your plant may or may not survive. Take precautions now to thwart this pest.

8 comments on “Protecting Your Squash Plants from Squash Vine Borers

  1. gene solyntjes says:

    Hello Jannine, I will definitely be folowing these directions, the problem is WHEN! I havea lot of pumkins, squash and gourds and they are growing pretty impressively every single day. Yet, they are nowhere near the size of the stems which were wrapped in the video.

    This preventative measure is very valuable, thanks for showing it to us.

    Gene S.


    • Gene-I forgot to mention that while the squash is small before they blossom, I keep them covered with row cover which keeps both the SVB and the squash bugs out but once the plants blossoms, we have to take the row cover off for the bees to be able to pollinate them-that’s when we should use the foil..


  2. las artes says:

    The squash vine borer overwinters as a fully-grown larva in cocoons in the soil, 2 to 15 cm (1 to 6 inches) deep. It pupates in the spring and the adult (a moth) emerges in June. These moths are distinct in that they are active during the daytime, resting on leaves in the evening; most moths are active at night. The moths fly slowly in zig-zags around plants and lay eggs singly on stems; eggs are usually found on the main stem near the base, but are also found on leafstalks or on the undersides of leaves. Moths are active for about one month. Eggs hatch in 9 to 14 days. Larvae enter the stem at the plant base within a few hours after hatching from the eggs. Larvae feed inside the stem for four to six weeks. Fully-grown larvae leave the stems and crawl into the soil to pupate. There is usually one generation per year, but a partial or complete second generation is possible.


    • Thank you for this great information. It will help us who have squash or pumpkins. It is always important to know the life cycle of the pests so we can be on the lookout for when they are active and possibly thwart them.


  3. Mike and I loved your class yesterday! We are out in the garden with our pest control hand out sheets in hand getting rid of our flea beetles!


  4. Christian says:

    I’ve had problems with SVB too,and am thinking of a strategy for next year. I am thinking that row covers are definitely the way to go at least until the female flowers show up. Once the flowers show up, you mention burying vines and/or wrapping in foil. So which one do you think you’ll actually use? I don’t see how both together would make sense. I would think the burying would be the better choice since it encourages more root growth at the nodes.
    But I see a few issues though, even with burying…. In my experience, the SVB moth don’t just lay eggs on the main vine. They lay eggs on the leaf stalks too. And the larva then enter the main vine by tunneling through the leaf stalks and into the main vine. If the vine is buried, then you cant see the damage, and your main vine would get infested and you would not know.
    I have had this happen this year. I have not used row covers but have instead just actively dug in vines, and picked off eggs when I see them. But I have missed a few, and have discovered some damage on some buried vines. I think the additional root development has helped the vine survive.
    But I am thinking that if I get a good head-start by using row covers, and then bury vines as they grow, I should have strong plants by the time I uncover the plants, that should be able to withstand some SVB damage until I get a good pumpkin harvest. Some vigilance by removing any eggs I see would buy me more time too.


    • Row cover is best as you mentioned till the female blossoms occur. Then for zucchini I try to cover the stem with foil but for winter squash and pumpkins I bury the vines as I can get the vines to lay down flat (forget it with zuks-they always stand up it seems) And burying the vines will help the plant make new roots at each leaf nodule which does help the plant with uptake of more water and survival as you mentioned – another reason to bury them-although this is alot of work. I have also tried keeping all under row cover and just uncovered them for a few hours each morning for the bees to visit and then recover it. That way the plants got pollinated and still were protected. I got lots of fruit still and not SVB but I may have been lucky. It takes a lot of row cover too!


      • Christian says:

        Yeah that may be the way to go, but I’ll need to convince my wife to go out and cover up the plants again after a certain time, or maybe just hand-pollinate and forget about depending on the bees.


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