Trying to control squash bugs can seem an insurmountable task when you find them in your vegetable garden. These bugs can do a huge amount of damage, particularly to young plants.
These 10 easy tips will keep your garden pest-free. Take charge and get rid of these destructive pests for good.
Last summer I had a huge zucchini and squash patch. It wasn’t long before I had a squash bug infestation. The bugs are easy to identify based on their distinctive eggs which the bugs lay on the leaves that they enjoy eating.
What are squash bugs?
The botanical name for squash bugs is Anasa tristis. This bug is very common in the USA and gets its common name from the fact that it is attracted to and lays its eggs on squash, as well as pumpkin plants. I’ve also seen the bugs on cucumber plants and other curcubits such as melons.
The adult squash bugs measure about 5/8 inch long and about 1/3 inch across. Their color varies from dark brown to dark gray. Their eggs are elliptical shaped and have a yellowish color to them. They are small – about 1/16 inch in size.
Normally these eggs are on the underside of the leaves but the ones on my plant were in plain sight on top!
Squash bugs suck the sap out of leaves of plants that they feast on. This causes yellow spots and will turn brown and can cause the plant to wilt. They do most of their damage on younger plants. (more mature plants seem to be able to withstand their feeding a bit better but can still be badly damaged by the pest.)
The key to the control of squash bugs is to interrupt their life cycle, since they have just one generation each year. The females live over the winter in plant debris and then come out in the spring to lay their reddish browns eggs on the leaves of cucumber, squash, melons and pumpkins.
Tips to Control Squash bugs
Attempts at preventing squash bugs seem to work best if treatment takes place when the plants are young and also when they are flowering. Early detection of squash bug nymphs is very important. One you have a big infestation of adults, they can be very difficult to kill.
Here are some ways to try and eliminate squash bugs infestations and some ideas for organic squash bug control:
Garden Cleanliness
The adult bugs are attracted by garden refuse. Remove vines, leaves and plant debris in the last fall and destroy it. This will ensure that their will not be areas in your garden that attract the bugs when it is time to plant your vegetable garden.
It is tempting to leave vines and debris until spring once the gardens stop producing, but doing this just gives bugs and disease a breeding ground. Time spent cleaning away vines and dead plants in fall will reward you with less problems next year.
Garden refuse can be recycled in a compost pile, but don’t have it too close to the areas where you will be planting your vegetables.
Don’t compost your dead plants in the fall. Those little pests have a tendency to overwinter and will cause trouble all over again the next growing season.
Practice crop rotation
Many garden problems occur when you plant the vegetables your garden in the same spot each year. Instead, rotate the crops often, so that the bugs and diseases don’t get a change to really take hold.
It is good to rotate your crops each year, replacing those varieties that are prone to infestation in a planting area where squash bug resistant varieties were grown the year before (or where other crops grew which are not affected by this pest.)
Mulch can harbor bugs
We all love mulch for its ability to control weeds and conserve moisture, but mulch can also attract squash bugs. Bare soil in vegetable gardens seems to work better for me than mulched soil.
Squash bugs love to hide under the mulch and use it as a protective cover. If you do want to use it in your vegetable garden, don’t lay the mulch right up to the base of the plant. (a good idea with mulching any plants.)
Squash bug resistant varieties
If possible search out plant varieties that are resistant to squash bugs. There are some squash types are seem to not be so easily infected by them. These varieties are good choices:
- Butternut
- Early Summer Crookneck
- Improved Green Hubbard
- Royal Acorn
If you can’t find resistant types in your store, be sure to inspect the undersides of the leaves often for eggs clusters and destroy the infested leaves.
Timing Matters
Planting squash a bit later in the season works if you have the time for this and your growing season is long enough. The majority of the bugs will have hatched and perished by then.
For this reason, a second planting often does better than the first!
Companion Plants that repel squash bugs
There are some plants and herbs which squash bugs seem to avoid, so planting them near squash and other curcubits is a good idea. These include:
- Mint (in containers is best. Mint can be quite invasive.)
- Chives
- Garlic
- Onion
- Tansy
- Radishes
- Nasturtiums
- Marigolds (calendula)
- Bee balm
- Dill
Attract beneficial insects
There are some insects are very beneficial to have on your side when you are fighting pests. One of these is the Tachinid Fly (Trichopoda pennipes.) The bug is also known as the caterpillar fly. This fly also helps to control Japanese beetles and grasshoppers and a few other pests.
This little bug can be very effective in helping to control squash bug populations. The female fly lays her eggs on the adult squash bugs. When the eggs hatch, they burrow into the squash bug to feed, eventually killing it.
To attract Tachinid Fly, plant dill, Queen Ann’s Lace, carrots, cilantro or calendula near your squash plants. They have pollen and flowers that will attract the fly.
Controlling Squash Bugs
Sometimes, even if you have practiced good garden cleanliness and planted wisely, you may wander out one day and find these bugs enjoying a meal of squash leaves. Instead of reaching for the insecticides, there are other things that you can do to prevent squash bugs from doing their damage.
Remove infestations immediately
Ignoring a squash bug infestation will just make it worse in the long run, since it will allow them to take over the plant. If you find infested leaves, remove them from the plant and destroy them.
Don’t forget to inspect cucumbers, melons and pumpkins. Squash bugs love them too!
Hand picking
Be vigilant with young plants. If you notice squash bugs on plants, hand picking of the bugs is very effective. Examine your plants often and crush the eggs when they are spotted. Be especially vigilant early in June, which is a common time for eggs to be laid.
To pick off the bugs, simply inspect the plants and pick off any adult bugs you may find and drop them into the soapy water. You will generally find the bugs on the underside of the leaves, or at the base of the plants.
Using wide packing tape with the sticky side out is also a great way to pick the bugs off the plants.
This can be a daily job and if you get decide to let it go for a few days, you may end up with a problem that is not so easy to control.
Insecticide for Squash bugs
With vigilance, insecticides are often not necessary but if you do develop an infestation that you cannot manually control, you may need to use them. 
Neem oil for squash bugs is a natural pesticide which effectively controls this pest. Spray it on all leaf and stem surfaces as the label suggests.
Diatomaceous earth applications around the base of the plant can be an effective method to control squash bug and is a treatment that is also considered Organic.
This powder does not work as well on adult squash bugs because of their hard shell, but it does help get rid of the squash bug nymphs.
Be careful not to get diatomaceous earth on the blossoms of the plants, because it won’t be able to tell the difference between a squash bug and other, more beneficial, insects which are attracted to pollen of flowers.
With a bit of care in both planting and tending of your plants, you should find that you can control these pests for good this year.
For more information on other invasive pests, see this post.
Admin note: This post first appeared on my blog in June of 2013. I have updated the post with additional information and photos.
To remind yourself of this post later, pin this image to your gardening board on Pinterest.
What have you found effective in dealing with Squash bugs?
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Can you tell me how to control squash bores. I am assuming that is what got the squash, zucchini and pumpkins, the stems at the base of the plant seem to split and then disintegrate, leaves become like slime. I had no moths this year and have not had any squash bugs. I had giant size leaves and the one zucchini I got was a nice large one before I lost my plants. These are in containers off the ground, I treated well with diatomaceous earth and replanted plants. I have been spraying the base of the plants with garret juice and orange oil and so far so good. However I wanted to know what you thought if you have encountered this. I also have nematodes to put out this weekend. Thanks
Hi Sylvia. My experience is that they are very hard to manage. One thing that I Have read about doing is to place some yellow traps for the borer adults. Squash borers are attracted to yellow, so if you put out a yellow container filled with water, you make catch them in it. Most management programs for treating them try to deal with it before they enter the stem. Once inside, they are very hard to manage. Placing row covers on the plants early helps.
If you use insecticides, do it at the stem area when the vines start to run. Permethrin Is one commonly used.
Carol
You can also use yellow trap pans to detect squash vine borer adults. This can be any container (e.g. pan, pail, bowl) colored yellow and filled with water.
Is it necessary to actually destroy the squash bug eggs? If they are rubbed off of the leaves onto the ground will that suffice?
HI Pam I would not let them stay in the ground nearby. They do such damage if they hatch. You can squash them, brush them into a bucket of soapy water, or wrap wide duct tape around your hands (sticky side out) and pick them this way and then discard.
Carol
Many thanks Carol! I think I’ll try the duct tape trick for the eggs and also try some DE around the base of the plants. I can see starting zucchini or yellow squash from seed later in the season but the melons and winter squash seem to need all summer to bear fruit (we are zone 6). If it’s not one bug, it’s another!
My pleasure!
Hi Carol, My butternut squash did not do well in one of my raised beds. I had brocolli, cauliflower and cabbage growing there over the winter. I live in southern california. I read some where that squash did not like growing where there had been plants from cabbage family. I had tons of organic matter, worm castings, weekly worm tea and irrigated drip system and they just would not grow. Several died and I replaced them. Now that it is mid September they seem to be growing better. I has been really hot here and that is not normal. I guess I will have to plant them somewhere else next year. I am bummed because I have limited space and not not rotate crops.
Hi Julie. I have better luck with squash when it is not quite so hot too. Crop rotation can be quite important but I agree that it is hard if you have limited space. Carol
I just found one on my chives so now what lol
Hi Rebecca. Pull it off and kill it! Squash bugs don’t normally infest herbs. They like squash and pumpkins so it is probably a stray, but don’t take a chance. Carol
I use a hand held Black and Decker cordless vacuum and suck up the adult squash bugs. Duct tape works great for removing eggs, except it tears the leaves easily. A hardier summer squash that lasts longer through an infestation and is good when picked small, is round tatume squash. The vines grow like crazy.
Great idea on the vacuum Elaine.
I have had good luck spraying the squash bugs with a mixture of dish soap and water. This kills both the adults and the nymphs. But even with this, and picking the eggs I find off the leaves, they can still multiply. It’s a never ending battle! This year I’m going to try some diatomaceous earth also.
I have a bag of diatomaceous earth waiting to use as well!