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

Squash bugs can be the bane of a gardener’s existence! Here are tips on how to identify, control, and get rid of squash bugs in your garden.

What Are Squash Bugs?

Squash bugs are very difficult to manage once their numbers get out of control and can cause a lot of havoc.

They 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 and aphids.

Generally, they attack young tender plants and seedlings, causing them to wilt and die. However, they cause little damage to plants in late summer and fall.

Note: 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 adult suqsh bug is a flat-backed insect that’s fairly large (over ½-inch long). They are usually dark gray to dark brown.

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 congregate in groups on the undersides of leaves.

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

Squash bugs overwinter in dead leaves, vines, under boards, and even in buildings.

In early June, they mate, laying small clusters of eggs (about 20) on the undersides of the leaves and the females will continue to lay eggs through mid-summer. You’ll find adults beneath damaged leaves and near the plant crown, where they use their piercing mouthparts to suck out nutrients from the plant.

Photo Credit: University of Delaware Cooperative Extension. Squash bugs lay small brown eggs on the undersides of leaves.
Squash bugs lay small brown eggs on the undersides of leaves. Photo Credit: University of Delaware Cooperative Extension.

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 become very difficult to get rid of completely. 
  • Pick bugs off the plant early. Fill a bucket with water and liquid dish soap and flick bugs into soapy water. Once the bugs are dead, it’s fine to dump the water anywhere.
  • Pick egg masses off the plants in the morning and later in the day. 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 (or pieces of newspaper). During the night, both adults and nymphs will congregate underneath the board. Squash between two hard surfaces in the morning and dispose.
  • 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.
  • Remove plant debris during the growing season to reduce sites where squash bugs can hide. 

Using pesticides

Insecticides are not effective to manage squash bugs once they are adults, so don’t bother trying.

In the event that you catch the squash is wilting very early in the season and you catch this when eggs are hatching, then insectide application is probably needed to manage it. See your local garden center or cooperative extension service for controls that are locally approved. The best time to apply pesticides is early morning or late at night (during minimum bee activity). Be sure to spray underneath the leaves, where most squash bugs are found.

It is not necessary to treat squash bugs found in the garden during late summer or fall.

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 thick layers of mulches like straw or hay that provide an environment that these bugs seem to love.
  • Practice crop rotation.
  • Consider keeping squash plants covered until blossoming begins. Remove the cover for pollination needs. There is typically 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.
  • Clean up cucurbits and other plant matter in the fall to reduce the number of overwintering sites.

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Reader Comments

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Holes in all my growing

Holes in all my growing spaghetti squash. I picked them all not rip yet. What bug is it? And should I throw them all out?

Thank you for this article. I

Thank you for this article. I have many pumpkin and squash plants in my gardens and they're badly infested with these squash bugs. Last year, they destroyed all of my cucumbers, squashes and melons.
Should I just bail out on the rest of this year by harvesting the current produce and destroying the infected plants?
and if so, should I burn the plants or compost them. I always compost everything and during the frozen months of the last winter, one of my compost piles consistently maintained about 90 degrees Fahrenheit through subzero weather. In case they happen to like the warmth, I don't want to take a chance on the squash bugs breeding or overwintering in my composts awaiting my next crop.

Any advice is appreciated.
Thanks y'all.

squash bugs

to answer Jan Jack on May 31, 2021 - 8:00pm - I planted squash and cucumbers in mid to late June and I have squash bugs on the cucumber starts already .... early July ... My entire garden is late this year due to the weird unpredictable weather and the caterpillars have been a bane on the cabbage and kale. I may salvage some cabbage but the kale was a loss. Each year the insect onslaught is worse . I tried covering the plants with row covers over bent frames but the bugs found a way in any way. I've tried planting various flowering plants, and herbals suggested on gardening guides and it does not seem to make any difference. Each year I harvest less due to the crop pests. Also may have to hand pollinate the squash this year as the past two have had a dismal production.

Squash bug egg control

I read and tried wrapping my finger with duct tape. The eggs and the bugs stick to it, it works perfectly.

squash bugs and cucumber beetle.

There is a very simple way to avoid getting squash bugs and cucumber beetles at all. Simply do not sow your seeds until the middle of June. By the time your plants are up and have their first primary leaves those insects are long gone...on to other gardens where the food source is up and tasty. It will NOT DELAY your harvesting by much as it is warmer by mid June and the plants catch up quickly. I'm 76 and this was my grandfather's practice.

Squash bugs

I read about bay leaf treatment, tried it, ground up some old bay leaves to a powder, dusted one plant, and watched with glee as they all scrambled away.

Gardening in SW Florida

In response to Lynn LaMar, you are gardening in the wrong season. In zone 10 our growing season is the fall and winter. Zucchini's are hard to grow here in the best of times, but impossible in the heat and humidity of summer.

Squash bugs

You can also put fire or smoke ash in with seed or plant when you plant. It provides some prevention.

Pest control

We spray a neem oil and dish soap solution on everything including squash and pumpkin . This has been pretty effective . We have to spray every five days or so . This is an all natural option . We still do checks we get a few here and there. Check leaves for eggs pull those or scrap and burn leaves or put in neem solution.

Bugs

Believe it or not, at 69 years old I am a 'new gardener' in SW Florida, of all places. lol I researched what I could grow and where and how and I'm happy happy with my little garden BUT. I had planted only 5 zucchini plants since it's only me and I've already lost 3 with 1 more in the wings under destruction. I've read all about bugs and nothing seems to fit the description of what's happening to my plants. I've just started 3 more babies and they're coming up strong. I've done everything recommended short of "the board." I don't see anything except little black dots under the leaves in the morning and I remove and squash them. I just bought very expensive organic essential oil spray "Dr. Earth Final Stop" that has stopped nothing...Use food grade DE around the base and that seems to slow things down. Also, Mrs. Meyer's hand soap with water in a spray bottle also seems to slow things down. My tomatoes look fine. My beans look fine. I have containers of rosemary, mint and lavender stationed right next door, yet, the destruction continues. I have one little guy struggling to grow and he looks shriveled and done for. This is crazy!! What's next folks????

Zucchini Pests

The Editors's picture

Could you describe in more detail what’s happening to your plants? We may be able to help identify the culprit.

Aside from squash bugs, the other main pests of squash tend to be slugs (when plants are young) and squash vine borers (when plants are a little older). However, the issue could also be unrelated to pests—are they getting enough water, too much direct sun, etc.

Zucchini

Can I use Epsom salts when I plant the zucchini, putting it in the hole before I put plant in?

Epsom Salts

The Editors's picture

Generally, we would not recommend using Epsom salt in the garden. Studies have shown its use to be inconclusive at best, and too much magnesium (Epsom salt is magnesium sulfate) in the soil can actually cause more problems than you would otherwise be trying to solve.  

OMG

Lost everything this year besides 1 whole cantaloupe and the tomatoes. This was my second year of real growing and we composted the vines last year and these things just took off. This explains so much. I mostly planted everything they love and they killed every watermelon, cucumber, squash, and pumpkin plant. What a waste. Now I know how to prevent it! Thank You!

Squash bugs

Squash bugs (or so I thought) have zapped just about everything in my garden, including peppers, tomatoes, cucumbers and yellow squash. I sprayed heavily with Sevin but it doesn’t affect adults. Could I be dealing with some other bug that looks like a stink bug? Should I skip a year of planting a garden? I have 4 raised beds, 6’x16’ each 2’ tall. I am in middle Mississippi.

Squash Bugs

try using pyrethrum, you can get it I think at either Low's or Menards. I am sure that you can find it on line to at any organic garden supply store. Pyrethrum is a derivative of chrysanthemums, and in the pyrethrum for is a nerve agent against the squash bug and kills it within minutes of contact, also works on the nymphs.
If you find that you have a bad infestation and can not keep up with the egg search you can buy nematodes, I am not sure o which one but you spray the leaves especially on the bottom, however this year the squash bugs were laying eggs everywhere even on neighboring plants, so I spray the nematodes everywhere once I start seeing squash bugs, but the nematodes destroy the eggs.

Squash Bugs extermination

I had never even seen a squash bug in my backyard garden until this year when I saw a huge infestation on each of my 3 squash plants. After harvesting the last few zucchini, I dosed each plant with diatomaceous earth and turned each plant over and buried them all. No sign of any bugs since then. Will doing this kill them and deter them from coming back next spring?

Squash Bug Plague

The Editors's picture

Unfortunately, there’s no guarantee that they won’t return next year, especially if you grow squash plants again (or if your neighbors do). Adults overwinter in dead leaves and other plant matter, so make sure that you clean up around your garden to remove and expose any good hiding place to the elements. If they do return next year, consider taking a year off from squash and growing veggies that are less desirable to them, like leafy greens or root vegetables. 

The problem with Sevin insecticide

The health dangers and risks associated with using commercial insecticides far outweigh the convenience of "getting rid" of bugs. I'll take my chances with bugs over getting cancer anyday.

healthyworld.org/sevin.html

I have a ton of these

I have a ton of these all over my spaghetti squash and zucchini. We have sprayed multiple times to no avail. Any suggestions on what else to do would be appreciated.

Squash bugs

Nothing will help but manual removal of them. Also, get rid of the eggs. I have found that squishing them between my fingernails works, as does duct tape, rolled around your hand, sticky side out, to remove them from the plant.

"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.

Is the squash edible?

The answer is yes. I have a huge problem with squash bugs. I have sprayed multiple times and cant get rid of them. I have not had any problems with them affecting the edibility of the squash. My zucchini and spaghetti squash have been fine to eat. If the damage to the skin is severe, just peel the skin off. The fruit inside is fine.

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.

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