Shop Products
Houzz Logo Print
tedln

Squash Vine Borer

tedln
14 years ago

Last year, late in the growing season; I had an invasion of a bug that I was unable to identify. These bugs would fly out of the woods around my property in swarms late in the afternoon during the hottest part of the day. The swarms would hover over my tomato cages which had tomato vines and cucumber vines laying over the top of the cages. I could never find any form of damage to my plants and they flew more like wasps than anything else. I decided to not worry about them because they didn't seem to be hurting anything. The bugs would swarm back into the woods each day at sundown.

I was able to examine one up close this morning and noted that it was not a wasp, but some form of beatle or moth. It was about 3/4" long. It had a black head with dark gray wings that folded to the side of the body at rest. The body was a bright orange with six black dots in a straight row down the length of it's body. It seemed to fly onto the stems and leaves of my summer squash only.

When I looked it up on the internet, I found that it is a squash vine borer moth.

{{gwi:71808}}

This bug can kill your hollow vine crops by laying an egg in the soil near the base of a plant. About ten days later, the larvae emerges from the soil and bores into the vine stem near the base. At that point it enters the stem and begins to feed. The plant at this time will begin wilting and will probably die in a short time. Once a larvae enters the stem, there are practically no methods to save the vine. The most effective treatment seems to be intervening in the life cycle of the moth by placing some material like aluminum foil or black mulch cloth around the base of the plant to prevent the moth from laying the egg or prevent the larvae from emerging from the soil.

Some pesticides are effective when applied to the soil around the plant. Do not apply them to the plant. Sevin (carboryl) and Bifenthrin (Ortho Max) seem to perform best with the longest lasting effects on the preemergence and post emergence larvae.

Ted

Comments (9)

  • carolinagardendawg
    14 years ago

    Nasty little critters! I moved into my current house 5 years ago...had squash and zuchs the first year. The next 2 tries were futile...all the plants succumbed to a SVB death just as fruit began to ripen. I gave it a break the past 2 years, but am trying again this year...I just seeded, hoping to get my plants up AFTER the primary hatching period. I'll also try the aluminum foil trick and will also wrap my stems tightly with floating row cover (a friend said she's had luck with this technique). And you're right, they swarm...in a real menacing way. My wife pulled out a tennis raquet one year and began swinging away.

  • Karen Pease
    14 years ago

    SVB is a frequent source of terror that is discussed often at this board ;)

    Best of luck to you in protecting your plants from this scourge!

  • bomber095
    14 years ago

    Ugh, hate those @%^$#! things.... I once heard that a solution of skim milk and water (1:3 water to milk ratio) will control SVB, but never tried it myself

  • Karen Pease
    14 years ago

    I once heard that a solution of skim milk and water (1:3 water to milk ratio) will control SVB, but never tried it myself

    No, that's for powdery mildew. And it's been peer-reviewed for that purpose, too. But not for SVB ;)

  • korney19
    14 years ago

    For best results, you really need heavy duty chemicals to kill the SVB. Best so far is lambda-cyhalothrin, in trade named products like Scimitar or Warrior. Second best was esfenvalerate which is the active ingredient in certain Bug-B-Gon formulas (I think the concentrate had esfenvalerate, the RTUs had something else.) Warrior is often used on other things like corn & tomatoes.

    The next best method is sitting in your garden with a fly swatter all day.

    Also, I should mention that contrary to what was posted above, the moth lays eggs ON the vine/plant, the eggs hatch, the larvae bore into the plant, eat it "inside-out" and THEN go into the ground to pupate. The problem persists because they hatch as adult moths in YOUR garden the NEXT cycle or year!

    The problem is that they lay the eggs 1 or 2 at a time/location, and usually in hard to see or hard to reach spots. These pics were results of spending HOURS lying on a piece of cardboard inspecting vines for eggs.

    {{gwi:43254}}

    {{gwi:71809}}

    All these pics were on 1 Atlantic Giant pumpkin plant... the lower left were eggs on roots that emerged from a node--the roots got exposed from wind blowing the leaves and lifting the roots out of the loose soil/compost. They also laid eggs on undersides of leaves as well as bases of leaf stalks. Burying the vines ONLY after careful inspection helps a lot too, but only if you are sure they are free of any attached eggs. This isn't practical on many varieties.

    Hope this helps.

    Mark

  • austransplant
    14 years ago

    One way to combat the borer without resorting to the chemical arsenal is to plant forms of squash that are resistant to it because of their hard stems. The varieties that belong to the species cucurbita moschata are like this; other cucurbita species, including the common cucurbita pepo (which is what most zucchini is), will succumb to the borer. This applies also to winter squash and pumpkins. For summer squash try the Italian tromboncino squash. In my view, seed or plant companies that do not tell you the scientific name of the varieties they sell should only be patronized as a last resort.

  • angie83
    14 years ago

    I planted plants they hate and it worked line your squash with radishes and nasturtium this year I have seen one of the nasty bugs and have grown a few squash and cucumbers but my tomatoes are choaking everything out hehehe Last year they wiped everything out ...so cheers to Nasturtiums and radishes

  • kasiaw
    14 years ago

    I'm not certain that radishes repel squash vine borers. I spotted one specimen when it was resting in the middle of a radish row.

    I have been spraying rotenone on the stems, injecting vines with BT on weekly basis, and picking any eggs that I spot whenever I have a chance. That has been going on for five weeks and the egg-laying period for the first generation is drawing to a close or may be over by now. Sprays and injections seem to work quite well, but several eggs did manage to escape control and I needed to remove larvae from lateral stems of one Blue Hubbard specimen I'm growing. However, the plant alive and quite healthy, and I have not lost any zucchini, yellow squash, or patison plants so far.

    And yes, C. moschata cultivars are quite resistant to the borers. They still can get infested, but damage is limited and I am yet to see a single specimen of butternut or other squashes of this species die from borer infestation.

  • tedln
    Original Author
    14 years ago

    Last year, when I was experiencing huge swarms of the critters; I didn't experience any plant losses to them. I always check the seed packets of everything I buy for resistance to common pests and diseases. I grew Burpee Pic & Pic summer squash last year and this year and haven't lost any so far.

    I grew four varieties of cucumber last year and determined that the Burpee Early Pride was the only one that stayed sweet all summer long no matter how large they grew. The others would eventually become bitter. This year, when I went to purchase my seed off the rack, they didn't have the Early Pride, so I bought the Burpee Sweet Burpless Hybrid. The next day, they had some Early Pride, so I wound up planting both and the Sweet Burpless Hybrid is way out performing the Early Pride in time to harvest and taste. I didn't lose any cucumbers to the SB pests last year and so far, I haven't this year.

    I think my selection of seed is the primary reason my plants seem resistant. It may just be early season luck.

    Another thing I do that may be helping is I watch for any problems with my plant leaves. When a squash leaf or cucumber leaf shows any sign of yellowing or getting powdery mildew, it gets cut off and disposed of. I think this may prevent many problems from getting out of hand.

    Ted