Squash Bugs

How to Identify and Get Rid of Squash Bugs

squash-bugs-pests

The squash bug is sometimes confused with a stink bug, but it can cause much more damage to your plants.

Barbara Pleasant

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What are those bugs on your squash? Squash bugs, probably. Here are tips on how to identify, control, and get rid of squash bugs in your garden.

What are Squash Bugs?

Squash bugs can be the bane of a gardener’s existence! They are very difficult to manage and can cause a lot of havoc. Squash bugs are most commonly found on squash plants (hence the name) such as zucchini, winter squash, and pumpkins, but they may also affect other crops in the cucurbit family (like cucumbers, cantaloupe, and watermelon). Other pests that are commonly found on squash include squash vine borers.

Squash bugs are often mistaken for stink bugs, as they are similar in appearance and both have a foul odor when squashed. However, stink bugs are wider and rounder than squash bugs.

Identification

How to Identify Squash Bugs

The squash bug is fairly large (over ½-inch long) with a brownish or gray body and flat back. The edges and undersides of the abdomen have orange stripes. They are able to fly, but they often simply walk around on plants. Young squash bugs, or squash bug nymphs, are gray and have black legs. They move quickly and often in groups on the undersides of leaves.

squash-bug-nymphs.jpg
Photo Credit: University of Massachusetts Amherst. Newly-hatched squash bug nymphs are small with black legs and move around in groups.

Squash bugs overwinter in your dead leaves, vines, under boards, and even in buildings. They fly to garden plants to mate as soon as vines start forming, and they lay egg masses on the undersides of the leaves. You’ll find adults beneath damaged leaves and near the plant crown.

adult-squash-bug-identiication
Photo Credit: University of Delaware Cooperative Extension. Squash bugs lay small brown eggs on the undersides of leaves.

Squash Bug Damage

These bugs inject a toxin into the plant and suck the sap right out of it with their sharp, sucking mouthparts. This causes yellow spots that eventually turn brown. The leaves will wilt because the damage prevents the flow of nutrients to the leaves, and then they will dry up and turn black, crisp, and brittle. The leaves also sometimes have ragged holes. Smaller plants will die, and squash bug feeding can decimate young fruit.

The wilting can resemble bacterial wilt, which is a disease spread by cucumber beetles (yet another squash pest), so be sure to find the bugs or eggs and identify them correctly.

Control and Prevention

How to Get Rid of Squash Bugs

  • Early detection is critical! You want to catch squash bugs before they grow into adults or they are very difficult to get rid of completely.
  • Pick egg masses off the plants in the morning and later in the day. One reader fills a vase with water and liquid dish soap and flicks the squash bugs into the water. Once the bugs are dead, it’s fine to dump the water anywhere. You can also simply scrape the eggs off the leaves with a butter knife and let them fall onto the ground, where beetles will eat them. Eggs hatch in about ten days, so be sure to check for them on at least a weekly basis.
  • Place a board or shingle in the garden at night. During the night, both adults and nymphs will congregate underneath the board. Squash between two hard surfaces in the morning and dispose.
  • Insecticides (such as carbaryl/Sevin) are most effective if applied when eggs are hatching. See your local garden center or cooperative extension service for controls that are locally approved.
  • Keep checking your plants, at least daily. If there are no more than a few vines infected, keep collecting and destroying the bugs and crushing the egg clusters that you find on the undersides of leaves.

Squash bugs on pumpkin

How to Prevent Squash Bugs

  • Prevention is key: In the fall, be sure to burn or compost old squash vines to rid your garden of any possible shelters for breeding and over-wintering.
  • Avoid deep, cool mulches like straw or hay that provide an environment that these bugs seem to love.
  • Practice crop rotation.
  • Consider keeping vines covered until blossoming begins. Remove the cover for pollination needs. There is only one generation of squash bugs per year, and you can avoid them by covering your plants for the first month of spring. You can also delay planting your squash until the early months of summer.
  • Companion planting can be useful in repelling squash bugs. Try planting nasturtium and tansy around your plants that are commonly affected by squash bugs.
  • Select varieties of squash that are resistant to the squash bug if you have a big problem. ‘Butternut’, ‘Royal Acorn’, and ‘Sweet Cheese’ varieties are all more resistant to squash bugs.

Plants Affected

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Reader Comments

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"Getting Around" Squash bug infestation

A gardener friend told me to plant icicle radishes as soon in Spring as possible, in a circle large enough to plant squash/etc. in. Wait till the radishes bloom (let them 'go to seed') then or slightly after the first of June (we live in zone 7) plant your squash. By that time either the squash bugs will have moved on, died out for the season, or been repelled by the radishes allowed to bloom. I've tried this with some success. Have run into a few late hatching squash bugs, but in such a decreased number that I could easily trap them under boards and/or pick them off.
Gardeners seem to/tend to have a 'bragging rights' attitude toward who plants what the earliest or first. Forget it. Plant later...and the squash bugs, for the most part, will have gone to your earlier planting competitors!

squash bugs

I checked my spaghetti squash the other day and had a bunch of small bugs on running around on the squash. They were and I assumed that they were young squash bugs. The squash was ready to be picked so I picked them and cut out the vines. My question is, does the presence of these bugs effect the edibility of the squash or other fruit that they may live on.

squash bugs

I didn't plant any vines and I bought 2 pumpkins the other day and they have squash bugs on them eating the pumpkins is that normal?

Squash Bugs

The Editors's picture

Sometimes pests will hitch a ride on crops after they’re harvested and shipped out to stores. Remove the bugs from the pumpkins and they won’t be a problem.

squash bugs

I will not use insecticides, so I experimented this year with DE. Fantastic experience...works on cucumbers as well. Fewer ticks in the leaf mulch that we use...? Can that be a real thing?

Diatomaceous Earth (DE)

The Editors's picture

The only thing you have to consider when using DE is that it will also kill pollinators (bees, butterflies, etc.) if sprinkled on and around flowers. Therefore, it’s recommended that you only use DE on garden plants when they are not in flower or when you can ensure that pollinators won’t accidentally come into contact with it.

Squash bug control

I've also had trouble with these pests on my peppers and certain flowers (yep - peppers). The only truly effective deterrent I've found is a product called BioNEEM, from Safer. Apparently, it disrupts the desire to reproduce and feed. VERY EFFECTIVE. I've found it to be effective on most garden pests, including grasshoppers. You can find it on Amazon. Check it out and good luck!

P.S.

Apparently, it's also an acceptable control for organic producers.

Squash bugs

DB the Product you mentioned by Safer was it Neem Oil?

DB is DE

I think you meant DE. Diatomaceous Earth. It's a natural silica the will shred internal organs of small pests. Be careful of your worm population also.

squash bugs

i use a combination of Murphy's oil soap and dish detergent that proves effective but the board technique was new to me.

How to Identify and Get Rid of Squash Bugs

I am surprised and frankly dismayed that Sevin or such heavy duty chemical pesticide was suggested as a control for squash bugs in an otherwise very informative article. I would suggest there are other more natural sprays that an organic grower (backyard gardeners too) can use to effectively deal with squash bugs. (Garlic sprays and also Dr. Bronner's Peppermint & Hemp Castile Soap - for a couple controls - are what we use on our small farm in Nevad, when all else seems to fail. Thanks for listening; Virginia, at Custom Gardens Organic Farm.

This always works for me

I plant radishes in succession every two weeks amongst my squash plants throughout the season and the squash bugs stay away. I started this after a couple of seasons of crazy invasions. If I only plant them once, it doesn't help. As soon as the radishes start to mature, the bugs are back. I discovered this by accident and went back to my garden diary to make sure nothing else had changed, but this was it. For me, it is a surefire squash bug repellent, though, I have to say it makes no sense to me either.

Squash bugs like tomatoes too

You didn’t mention it, but squash bugs love tomatoes as well. They are always on my tomatoes, eating the surface, although that may not be what initially drew them to my garden.

So many squash bugs

For 3 years now, after planting at the beginning of May I religiously go out and pick squash bugs off all my vining plants; Squash, butternut squash, cantaloupe, cucumbers, pumpkins, zucchini, and even pole beans, this morning I even found them on my bell peppers, and I drop them in a soapy solution. I have filled two, gallon sized, bottles with these bugs and their carcasses and still they are everywhere. I have companion planted, sprayed Neem oil, sprayed organic soap, scraped off eggs and they are still everywhere. Right now my routine is to gently spray down the plants, to get the bugs to come to the tops of the leafs and then hand pick them. Then I go back and check for eggs and once ever couple of days spray a soapy solution and/or neem oil on the vines and leafs. I have even used sevin in a pinch.
In the garden I do not use mulch and have placed stone around the raised beds. In the winter I do a complete clean out and burn the vines giving them no place to bed over the winter. This year is the first year I have been able to keep the majority of my vining plants alive, although all the zucchini plant succumb to them.
Help me! PLEASE
In the article you state there is only one generation per/year, what do you mean by that?
How can I finally rid myself of these things?

Squash Bugs

I’ve pulled all my zucchini and squash plants for the season. I had squash bugs but the plants were hearty and still grew several zucchini and yellow squash from each plant. I’ve been using a fly swatter to kill the bugs when I saw them and now that the plants are gone will the bugs go away? Do they hibernate in the winter? I live in Utah so it will be cold, will that help kill them off? Any advice will be appreciated.

Squash bugs

Wow!
After reading these responses, it sounds hopeless!
You can never find all of the bugs and eggs to pick off, and spraying kills the bees!
Actually no acceptable solution here !
☹️

It's not hopeless, just kinda hard.

Neem oil in water with a little bit of soap as a wetting agent in a spray bottle. Thoroughly spray every week or so, more if the infestation is bad. It may not totally get rid of them at first because they proliferate so quickly in the spring, but it will keep them under control and eventually you'll get the upper hand. It is only dangerous to "bad" bugs, in that only the ones that eat the plant are effected by it. It also helps with powdery mildew.

squash bug or kissing bug?

How do you tell the difference between a squash bug and triatominae? The one I photographed was mostly yellow, not so much brown as squash bug...

squash bugs

I placed plastic bowls between each plant, in them I put some water and a little squirt of dish soap. The next day each bowl had a squash bug or bugs. I changed the water every other day. I made up a quart of squeezed garlic, with cayenne pepper, Tbsp, maybe, just dumped it in, and a squeeze of dish soap. Poured that around the stem every other day. Bug are essentially gone. Found a couple small deposits of eggs, but not the dozens that would be here by now. I'm checking for eggs every other day. The adult bugs are dead in the soap water. But our season is just getting going. I see below someone used Neem oil and I'm going to add that.

squash bugs

I didn't add to fill the quart with water after putting in the garlic and cayenne and soap.

squash bugs

Was wondering if anyone has had any luck using diatomaceous earth on plants, eggs, adults and whatever? Thanks

Diatomaceous Earth

Diatomaceous earth (DE) will kill squash bug adults and nymphs, but because it will need to be applied to the leaves and stems of plants to be effective, there’s also a chance that it will kill pollinators, like bees and butterflies, as well as other beneficial insects, like ladybugs. If you do apply it to plants, apply it in the early morning or late evening and avoid applying it on or near flowers.

If I cut the leaves that have

If I cut the leaves that have a few eggs on them will that harm the overall plant??

Cutting Leaves

Removing an entire leaf would be overkill; it’s better to just squish the eggs. Cutting the leaves could expose the plant to viruses and mold.

Squash bugs

I am reluctant to use DE in the garden, because it will harm pollinators and earthworms. No one has mentioned praying mantis or Asian wasps as a control method. Would this be a realistic solution?

I have tried the Diatomaceous

I have tried the Diatomaceous Earth & for the most part it did work. However I just checked on my plants today & the little buggers seemed to lay eggs on the belly of a few leaves. I will try again. I also did not know if I cut the leaves that had the eggs on them & then dusted if that would be effective too???

DE for Squash bugs

I have used DE for these bugs. It does not work on adults or eggs just the nymphs that have thin skins. The de will scratch the shell of the bug and dehydrate them, You must reapply after it rains,

"Squash bugs" please help!

I've found bugs and eggs on my gourd plants. I'm not sure if they're squash bugs even though the description seems to match the pictures vary slightly. The adults I'm finding are black in the front and back with orange on the outter mid section of the bug. The eggs are mostly under the leaves but not always. There seems to be tons of dark green eggs as well as some lighter cream colored which are almost white. Please help me identify these critters so I can try to get rid of them! I wish I could share a picture here of what I've found! Thank you.

Killing Squash bugs

I do something I have never seen mentioned as a way to kill squash bugs. I spray the plants and ground thoroughly. Then I wait a couple of minutes. The squash bugs begin climbing to the top of the leaves--I assume to get dry. Wearing gloves I simply squash the bugs and lay them out for a "body count." By the time I get to one end of the plants, more bugs have climbed to the top of the other end. I repeat going down the row until there are no more bugs. If I have time, I soak the ground and plants again just to make sure. It worked until I missed a day, then the plants suffered.

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