my recent adventure with squash bugs

ADD THEM TO THE LIST of creatures I’ve had to stalk in my rounds each day through the garden, things I’ve been squishing or drowning in the hopes of having a harvest of favorite crops myself–and not letting insect pests eat it all first. One enemy on the scene that I seem to now have under control: the squash bug (who looks a lot like the hated stink bug, but isn’t).

The most common “squash bug” is Anasa tristis. I even have some that overwinter in my house (along with Asian lady beetles and stink bugs–whee!). I love that its Latin species name, tristis, means sad–which is what it was making me a couple of weeks ago when I was picking these guys off regularly. (A side note: I wondered if I actually had the helmeted squash bug, Euthochtha galeator; an almost-lookaline, but caught some and really examined closely.) Anasa prefers lay its eggs on the foliage of squash and pumpkins (but in a pinch will eat foliage of other cucurbits); some varieties are more resistant than others to its trouble-making, one of those being ‘Butternut.’

Though for long it was not thought to be a spreader of bacterial disease—the way the cucumber beetle is—in recent years Anasa tristis has in fact been identified as a vector of yellow vine decline (a pdf on that, from the University of Kentucky, is here).

Even without that more serious potential outcome, an unchecked infestation of squash bugs will pierce and suck on leaves, causing damage and wilt of a non-bacterial kind—and eventually leaf necrosis—and will even damage the skins of fruits later in the season. Watch carefully in spring (later May and through June here, especially)—the first sign will be small yellowish or brown dots (above), or if things have already progressed, some wilting.

The key to managing squash bugs is to not let them build up—meaning strict cleanup in the fall to reduce overwintering of unmated adults, and prompt attention in the spring, when young plants are especially susceptible and insect populations are rising. Check the undersides of leaves daily for egg masses or nymphs (recently hatched bugs); you can see what each stage—egg, various nymphs, adult—looks like on the University of Minnesota Extension site here. Either I got all the overwintered adults just as they awoke (before they reproduced) or there weren’t many, because a week of vigilance last month seems to have rid me of any serious troubles, and my plants are now fine.

I was able to catch adults in the early part of the day near the base of the plants or under leaves, and you can lure them to hide under boards or shingles at night much like you would slugs by day, but they move much faster once fully active. “Empty” your traps first thing daily.

Growing resistant varieties is recommended. Besides ‘Butternut,’ the University of Arkansas suggests ‘Royal Acorn,’ ‘Sweet Cheese,’ ‘Green-striped Cushaw,’ ‘Pink Banana,’ and ‘Black Zucchini.’

And then there is the tactic of succession sowing—one of the best defenses a gardener has against wholesale loss of any crop, really. Plan to have multiple sowings coming along—not all your cucurbits at the same stage of development at once, potentially coinciding with the worst invasion. When I saw the first squash bugs, I made a note to plant another hill of squash just in case I failed to thwart the pests on the original plants.

Even if I hadn’t seen those squash bugs, a late sowing would be a good idea–a summer planting of a bush variety of squash or two. After all, who knows what pest will move in next–or perhaps in a hot, dry season like this the early plants will simply poop out (like the gardener feels like doing about now).

expert help with squash and other cucurbits


    1. margaret says:

      Hi, Dru. Yes! My next generation are up and developing nicely, Hooray.

      Hi, Gillian. Well, I certainly do hope so…trying not to lose my optimism over here at the moment.

      Thank you, Reed. Not sure what has come over me, but lately I am always asking myself “what’s that?” about critters I have just barely noticed except to drop into a bucket of water before. Magical, the world of insects, really, once you dig in.

  1. Roberta says:

    Oh, my. It’s bad enough that there are squash bugs but now to find out that there are a variety of squash bugs! What is a gardener to do? My problem in the garden happens to be leaf footed bugs. I’ve pretty much given up trying to eliminate them. In fact, I regularly walk past two that are sitting on a tomato, proud as can be, mating. It seems futile to knock them off at this point. C’est la vie.

    1. margaret says:

      Hi, Roberta. The squash bugs are a kind of leaf-footed bugs, I think. All in the family, right? It’s exhausting!

  2. Barbara says:

    Thanks so much for the link to the U of MN Extension Service. I found some “unidentified” little nymphs on my squash in the early am hours and didn’t hesitate to rid them of their breakfast. I’ve been squishing with delight their egg masses and now have the pleasure of squishing the nymphs. I’ve pretty much got down the ability to double hand clap the striped cucumber beetles if I’ve missed the predawn raid. I feel like a stealth bug ship destroyer…..would be a funny one for Andre!

  3. Dd says:

    I am always plagued by these and beetles every year!! So frustrating. What do you consider good cleanup at the end of the year?

  4. Louise says:

    I always enjoy reading your blog. I’ve lost a summer squash and a zucchini plant to squash vine borer. I replanted last week. We harvested the garlic several weeks ago. They are in a basket now but I guess I will be freezing it today. Virginia has been so hot. Today will be 101 degrees.

  5. Pamela J O'Leary says:

    I have had many squash bugs yet. I hope not to battle them this year. ther seem resistant to the produsts i have tried. And just picking them off is time consuming. iI tried Pyrerethene or something like that. My question is my heirloom tomatoes are some leaves are yellow and the fruit is rotten on the bottom. I am watering more effectively now that I have my drip system all hooked up correctly.and they are happier But still having some yellow leaves.what should I do to remedy this problem? thanks The fruit pn the squash has started and eggplant and cukes galore. yea Last year was dry year and nothing did well.

  6. p-- says:

    these pesky critters are a long-time, long-term problem with me. i haven’t even tried squash in years, and none of my neighbors grow anything, but there they are, regular as clockwork! it’s a small invasion so far, but enough that my zucchini and pumpkin have what little fruit i get dying on the vine. i remove the eggs and adults as i see them, but they come right back. grrrr!

  7. ann says:

    It is hot here,too but had a downpour yesterday. You know it is hot when 88 at end of week is cooling down. Had great success with cucumbers in straw bales but just didn’t want that much pickles this year..Never had bugs in cucurbits in North Dakota..

  8. Charlene says:

    Hoping someone here will have a definitive way to distinguish a predatory stink bug from the bad ones. I know this post was about squash bugs but I happen to be on a seemingly futile quest to determine if a new stink bug is good or bad. Having had several years of the most horrible infestation both outside and inside, I am anxious to find out before it’s too late. Thanks.

  9. Jo says:

    Having lost most of my winter squash to squash vine borers last year, this year I am trying a hint passed along by another person: burying several of the nodes along the main stem as they grow early in the season so that the plant also roots at those spots; that way, if the vine borer gets in there it may kill only a portion of the plant.

  10. Corey Lane says:

    Thanks for the info! I thought they were stink bugs too.
    I got a tip from the “garden guru” at my local Lowe’s that seemed to help. She told me to make a catnip tea by steeping catnip in boiling water for a few hours, and then spraying the squash leaves and plants. Apparently they don’t like the smell. Not sure how much science is actually behind this but I noticed a lot fewer nymphs in the days after spraying.

  11. Jo says:

    Another method for squash bug issues is to cover the plants with row covers until they flower (then removing the covers to make them available for pollination).

  12. narf7 says:

    I have to share what my friend told me…her hens ate every single one of her green vegetable bugs when she finally allowed them into her gated vegetable garden out of sheer frustration over what to do organically to control her bug problem. They were overwhelming her (the bugs NOT the hens ;) and so she just decided that it was better the hens ate the vegetables than the bugs…at least the hens were giving her eggs! The only thing that the bugs were giving her was coniptions! The hens scarfed the bugs and were too full to get stuck into the vegetables and were easily rounded up once satiated.

  13. Connie Webster says:

    Just discovered squash bug adults, eggs, and nymphs on my pumpkin plants this morning! I much appreciate your blog and links to resources.

  14. Susan says:

    About to throw in the trowel. Between squash bugs, groundhogs,and no rain, I haven’t got much garden left. Maybe a nap to dream of next year’s garden.

    1. margaret says:

      I do understand, Susan. Some years when it has been very dry or otherwise impossible, I will confess to simply yanking things out and erasing the stressful sight of stressed-out plants. Last week I did a ton more cutbacks, and there are bare spots everywhere — but better than looking at crispy brown leaves!

  15. Charlene says:

    Recently read to make a cardboard collar out of paper towel or toilet paper rolls (or gift wrap roll which is usually sturdier) to put around the squash stem. After doing so and wondering why wouldn’t they just attack the leaf stems still laying on the ground, I flattened cardboard boxes and laid all around the plants. I figured it would act like mulch as well. So far so good and keeping fingers crossed. Hope the cardboard doesn’t add anything bad to the soil. Anyway, thought I’d put this out there in case anyone else wants to try it. Now if I can only win the war with the stink bugs.

  16. Olivia Brady says:

    I didn’t check carefully or didn’t know what to look for and today I went out and my zucchini is totally gone. Bugs all over the place and on the spaghetti squash as well. Totally loss. It is an infestation and I am somewhat clueless as what to do. I got some insecticidal soap and ripped everything out but I am not sure what else to do.

    Will it be safe to plant something else there? Also if I plant anything in that bed will it be okay? I have some peppers growing there and an eggplant at the total opposite end of that bed. I will not plant squash in that bed next year.

    I have never had this happen before. Could have been from the straw that I put down a few days ago to help conserve water a bit? Need some advice here.

    Thanks so much for any help you can give me.

  17. Karen says:

    Squash Bugs
    a poem
    by karen

    Squash bugs,
    I hate them,
    they stink,
    and the only way I’ve found been able to kill them is to cut them in half with scissors.

    the end

    I’m sorry it doesn’t rhyme. Squash bugs make me angry and when I’m angry I lose my ability to rhyme.

    1. margaret says:

      Well, Karen, I’m not entirely sure that you will be named poet laureate anytime soon, but the verse is quite moving anyhow. (By the way the same technique is very effective with slugs, and they love more slowly so it’s easier to accomplish. Aren’t I horrible?)

  18. dirt says:

    Hello there. Amazing website!!!
    I heard of a method once for theese bugs and cuc bugs. It was to put out theese bugs most desirable plants early in the season. Wait until there are many on the plant. One morning very early bring out a bucket of hot soapy water. Pull up the whole plants and submerge them in the water.

    1. margaret says:

      Thank you, Dirt. Yes, great idea — technically called planting a “trap crop,” which farmers sometimes do at the edge of a field, then just treat that row or patch, not the whole crop. Thank you!

      Hi, Olivia. So sorry. I think the commenter just now named Dirt (tee hee) has a great idea, but it sounds like your plants are disposed of already. The bugs would like hiding under mulch, yes, and I would try to trap/kill as many as you can — can’t hurt to reduce the population, and in fact it will help, since unmated adults overwinter. Read up on their life cycle etc. here. You can replant the spot but not with a cuke, squash, pumpkin, melon of course. The key is to notice the first little signs of any issue and get them before them multiply, of course, easier said then done. I am pretty crazy inspecting my squash relatives when young, and also my cabbage relatives (for caterpillars) when young, otherwise those pests always get ahead of me.

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