There are lucky gardeners (some of them readers of TMG) who don’t even know what a squash bug looks like! But if you live in parts of the country that has a heavy population of them — like here in Virginia –you’ll never be rid of them 100% no matter what you do.
Non-organic gardeners may think that poisons are the answer, but that line of thought is a result of programing by marketing and lack of facts. If you’ll notice, the people that consider these poisons “safe” are the manufacturers and sellers of the poisons. Dumping poison on food to kill bugs and then ingesting it— is not something a knowledgeable, thinking person is going to do.
Defining “Winning the War”
In areas like ours where the squash bug is common — winning the war against squash bugs is defined as
- keeping the number under control by killing every one you can and
- getting a good harvest of squash
Combination of Strategies
To win this war usually takes a combination of strategies used consistently in order to get the desired results. And if you’re going to grow any cucurbits (squash, melons, gourds, cucumbers, pumpkins, luffas, watermelons) it’s a battle that’s constant and ongoing in areas where squash bugs are prevalent.
Choose a Strategy that’s Practical for You
Every proposed strategy is not suitable for everyone. There are some that I absolutely know would work for me, but for one reason or the other it may not be practical to use that strategy in my garden. Since things can change from year — one strategy that’s not practical this year — might be practical the next.
For this reason, I would suggest bookmarking this page and reviewing it from year to year.
Know Your Enemy
- When adult squash bugs come out of the soil in the spring, any females who didn’t lay all their eggs last year — can start laying eggs right away. So eggs can be on the plant before the overall population of bugs start to mate.
- After the other females mate, they can lay up to 250 eggs. They lay approximately 20 at a time. Usually eggs are on the underside of the leaf, but you’ll find them on top sometimes.
- Eggs can be bronze, black, or gold colored. They can be spaced apart or close together, but usually with an equidistant spacing arrangement. Bugs start feeding and laying eggs first on the part of the plant closest to the ground.
A Tip for Finding More Bugs: When you see those lower leaves start to shrivel, wilt, turn yellow, and then die — that’s usually squash bug damage. In the early morning and in the heat of the day, bugs will tend to congregate under these leaves. When you’re looking for squash bugs — this is the place to start.
- Eggs hatch in 7 to 9 days depending on temperatures. The young tend to feed in a group and stay right where they hatched. That doesn’t last long and each will move to different parts of the plant to feed. This is the part that makes early detection crucial. Once they start multiplying it makes your job much more difficult.
- The babies — (called nymphs) –go through 5 stages (called instars) before they become adults. This cycle takes about 6 to 8 weeks.
- The bugs will continue feeding on the plant and its fruit until frost! They over winter in the top 6 inches of the soil either in your garden or near by.
Your Most Important Tactic
Of all the tactics you use in your master plan to wage war on squash bugs the one that is first and foremost for success is the action you take to seek out and destroy squash bugs. You must be consistent in your “seek and destroy” mission to be successful.
If you can’t check twice a day, check once a day. If you can’t do that — check every other day. And certainly, I would recommend not going longer than every third day without looking for and destroying squash bugs and removing eggs.
Try to plan your checks in the early AM or late PM. Avoid handling the plants when they are wet with dew or rain. Diseases can spread very rapidly in those conditions.
Also avoid handling the plants in the high heat of a summer day. Plants are more stressed when the sun is hot and high. Many show it by wilting — since they’re giving off more water than they’re able to take up. You can loose plants by handling them when they are under stress. Just wait until the sun is low. They’ll recover in the evening.
My Plan of Attack
I’m in my garden twice each day and spend a few minutes each time finding and destroying squash bugs and removing the egg masses. I take my garden gloves with me and squash every adult and nymph squash bug I find.
First I check for bugs under the bottom leaves that show signs of damage and then I look under the other leaves. I find a lot of eggs right at the leaf base in between the veins of the leaf.
Alternative to squashing: Handpicking and placing the bugs in a small bowl of soapy water will kill them.
I literally tear the egg masses off of the leaves. And I put that part of the leaf in my pocket so that when I get to the house I can put it in a plastic bag, seal it, and put it in the trash.
Alternative to tearing the leaf: Remove the eggs with duct tape. Stick the tape on the eggs and pull off.
Important Note: The eggs will hatch even if they’re not on the plant. Flush them down the toilet or put them in a plastic bag and get them gone!
I only grow a few squash plants because I just don’t want to spend anymore time on this task. The more plants you have the longer it will take you check for squash bugs and eggs.
Sometimes I don’t even want to grow squash because of the squash bug. But if I don’t grow some squash — they will attack my cucumbers in full force and I’d rather keep them centered on the squash for easy checking. As the season progresses they can move to the cukes anyway, but the bug numbers are not as bad as if I had not raised squash. In effect the squash acts as a trap crop.
WATER as Part of your “Seek and Destroy” Strategy
If you have the use of a hose or water wand near your garden you can use water as part of your “seek and destroy” strategy.
Spray your plants — the under sides of leaves and around the roots. The water drives the squash bugs out in the open where you can destroy them by whatever method you’ve chosen.
Hand-held or Shop VACUUM
You can vacuum up bugs and possibly the eggs. This allows you to capture more bugs at once. This is particularly useful after you’ve used a spray of water to get larger numbers of the bugs out in the open. Also, lift those bottom leaves to get large numbers at one time.
IMPORTANT: Make sure you empty the vacuum and either destroy the contents (burning will work) or place in a sealed bag and take to the trash. Again, the eggs will hatch even if not on the plant.
Very inexpensive hand-held mini bug vacs are available just for this.
Boards and Burlap
Another tactic used to find and destroy greater numbers at one time is to place wood boards or pieces of burlap down around the plants in the evening. In the early AM and again in the heat of the day bugs take shelter there. Lift the boards or burlap and kill or vacuum up the bugs in numbers.
Floating row covers (row cover fabric) can be one of the best and most effective strategies for having squash all summer. With some diligence, they will protect from squash bugs (AND the squash vine borer). If you use this method here are some things to keep in mind:
- Plant in a section of the garden that did not have squash bugs (or squash vine borers) last year. You don’t want them coming out of the ground under your row covers.
- You’ll have to lift the row cover and hand-pollinate and then replace the cover.
- If you’re placing covers over squash that have been growing in the garden unprotected, check thoroughly to make sure there are no squash bugs or eggs before you cover them.
- Make sure they’re secure at the ground level so the bugs don’t go under them. (I would pile dirt on the fabric all around the edges.)
- Watch for tears and holes in the fabric that would allow the bugs to get in.
Tip: Devastating winds in some areas of the country are hard on row covers and hoop houses. Make sure the fabric is taut — no matter where you live. The more loose the fabric is — the more the wind can move it around.
There are always a lot of variables to consider in determining what method is just right for you.
For example: if your garden is as full as mine in the spring this tactic may not be practical until the fall when you can usually give the squash an entire row to themselves.
Trap Crops at the beginning of the season can work in tandem with other strategies like row cover fabric.
Try planting several squash plants a good distance from the ones in your garden under row covers. If you don’t plan to eat these you can use methods that maybe you wouldn’t use on ones you’ll eat. (I’ll talk more about that under Chemicals for Organic Gardens.) You’ll kill a lot of squash bugs and at the same time, insure greater success for the ones under the row covers.
End of the Season – Trap
Near of the end of the season – or when your plants are about done — squash bugs will amass on what remains. This is an opportunity not to be passed up. Killing off the remaining numbers will cut down on what you have to deal with next year by preventing this group from wintering-over in your garden or near your garden.
Check the plant remains everyday. New bugs will continue to gather on them. (I discussed this in a post last fall.) Use a chosen strategy to kill them.
One fellow who had a two row planting of squash, pulled up one plant at a time towards the ends of the season. He’d destroy that plant and give the bugs a day to congregate on the other plants. He continued this plan until only one plant remained with all the bugs on it. Then he used a Bernz-o-matic torch with the long nozzle and burned the plant and then all the compost and mulch nearby where the bugs might hide.
Obviously, this is something that takes care and planning. You don’t want to set your entire garden (or yard or house) on fire — or anything else for that matter. Safety is imperative if you use this method.
Growing in Containers
A strategy that has been successful for many gardeners is growing in containers or grow bags. Grow bags hold plants high enough off the ground that it’s easier to see and kill the squash bugs when performing “bug-checks”.
Container growing in combination with other strategies can be especially successful. For example, one gardener put some type of weed barrier on her lawn and then set the containers with the squash down on that. There was no place for squash bugs to escape or hide and if one was found it could easily be caught and killed.
Gayle, an experienced long-time gardener and reader of TMG has come up with a great combination-strategy using containers, water, diatomaceous earth and row cover fabric.
- She’s planted the squash in grow bags so that it was easy to capture and kill the first bugs she found.
- Searched for more bugs using a spray of water to dislodge any bugs that may have been hiding.
- Placed a ring of diatomaceous earth around the plants. (In addition, I would dust the base of the plants in case the squash bugs come down the stem from the top of the plant.)
- A cage built to go over each pot was covered securely with lightweight insect fabric.
- Daily checking is planned to see if the bugs have found their way inside the barrier.
- When the plants flower, she will hand pollinate.
If Gayle’s combination strategy is practical for you, I think it’s as close to perfect as any I’ve heard of.
Diatomaceous Earth (DE)
Diatomaceous Earth (DE) is all natural. It’s made from tiny fossilized water plants. Because of its microscopic razor sharp edges it can be lethal to insects. When dusted with DE, or when it is applied as a wettable powder spray, it can cut through a bug’s protective covering, dry them out, and kill them.
The insect must come in contact with the DE for it to effect them. It does not kill instantly. And – as with most things – some folks seems to have better luck with it than others. One user even observed that she had better luck with it where her soil was sandy and no luck with it where her soil was clay.
It’s best used discriminately in the garden because it can kill your beneficials as well as the bad guys. Using it on plants and trees that are flowering can kill your pollinators.
Some DE — even that approved for use in Organic Gardens — has pesticide bait added to it. To be safe, use only food grade DE.
As far as safety concerns for the gardener — avoid breathing the dust. Any foreign material that ends up in your lungs can be a carcinogen. It’s an irritant to skin and eyes as well. So just take precautions to be safe.
Dishwashing Liquid Spray
One of things that has really surprised me is reading of the success gardeners have had using a simple Dawn dish-washing liquid and water spray. (Be careful with Dawn and test first before spraying everything you have.) (I use a more gentle castile soap.)
One gardener even made a comparison to see if she could tell the difference between plants sprayed with dawn and water and another spray she had that contained organic pesticides. She found they both worked the same. Impressive.
This spray should kill the young almost instantly, but will take a few minutes to knock down the adults.
Here are 3 different recipes for a soap spray.
- The first is one tablespoon of liquid soap per gallon of water. If my math is correct this works out to one teaspoon per every 5 1/3 cups; 1/2 teaspoon for every 2 2/3 cups.
- Another recipe called for 1/4 inch soap in a small squirt bottle; then fill it with water. (They emphasized DO NOT SHAKE UP. I’m not just sure why — but I think I’ll follow this direction until I can see for myself.) After you spray the bugs they should start dying within minutes.
- Still another calls for a Kirk’s or Dr. Bronner’s Castile soap. They used the old fashioned hand (bar) soap rather than the liquid soap. Shave or grate about 1/3rd of the bar and let it dissolve in 32 oz. of hot or very warm water. Pour into spray bottle. They also suggest setting the spray setting between a stream of water and a mist to give a bit of foam with the spray.
- You still want to be careful to avoid spraying your pollinators and other beneficials. By spraying just before dark you will avoid most bees.
- Soap sprays should be sprayed directly on the bugs, NOT on your plants! Soap can do major damage to your plants especially during intense heat and sunlight. It can easily burn foliage and often won’t show up for a few days. So just be careful. You may want to test it on a lower leaf just to see what it will do.
Safer Brand makes an insect killing soap if you don’t want to make one yourself. But remember — it will still kill your plants under certain conditions so be very careful how you use it.
Example of a Possible Strategy using Soap/Water spray in your arsenal
- Look under bottom leaves first. Spray the bugs you find with the dawn solution (or the one of your choosing).
- Look under boards and burlap. Spray the bugs you find with the soap solution.
- Using the hose or water wand spray the entire plant with water to dislodge the bugs. Spray bugs with soap solution.
- Spray the mulch around the base with water to dislodge the bugs. Spray bugs with soap solution
- Vacuum the bugs.
- Look for and remove eggs.
A Home Made Insecticide — if the you have the stomach for it!
I read about this mixture in Organic Gardening Magazine more than 30 years when I was a fairly new gardener. Even if I had an old blender that I could use — I didn’t have the stomach to fix it. But many gardeners over the years have reported great results.
It’s my understanding that this method can be used for almost any insect pests. It’s said to work because most insects have a virus in them that will kill them. This mixture spreads the virus to other insects of the same family — in this case — the squash bug.
Kill and collect as many as you can of the insect you’re trying to kill. Add water and blend well. Let stand for 2 or 3 days. Strain off the liquid and use it to spray your squash.
Home Made Repellents
There are probably as many variations on these “old” repellent recipes that use chiles, onions and garlic as there are gardeners. They work to repel rather than kill, so you’ll still need to continue your “seek and destroy” program. The thing I wonder about is — if the squash bugs are repelled from the squash plants – or other curcubits you use the repellent on — will they go to other plants in the garden?
On a more positive note — I think these repellents would be excellent for the Squash Vine Borer! (I don’t know why, but I especially favor the first one and the third one for the SVB.)
- # 1 – Fill spray bottle with water and 2 tablespoons of Eucalyptus oil. Spray.
- # 2 -Make a solution with hot chile peppers and water. Let sit for 24 hours. Strain and spray.
- # 3 – Add onions, cayenne peppers, several garlic cloves and enough water to make a semi-liquid mixture. Whirl in blender. Let is sit for 24 hours. Add 1 tablespoon of the mix to 1 gallon of water and spray. (I’m not sure how one would keep the excess. 🙂 )
Natural Repellents to Plant in the Garden
Last year I read about onions being planted with squash to repel the squash bug. Since I plant lots of onions, I panted some with every squash plant I put in or out of the garden. I don’t know if it was effective. The squash bug seemed longer in showing up, but it did show up — and in its usual numbers.
I’ve read that nasturtiums are good to plant with squash, but I’ve also read that nasturtiums draw the squash bug — like a trap crop. This would not be the repellant crop for me.
Radishes planted with squash and left to go to seed are said to repel the squash bug. I’m doing this this year.
Tansy is said to be a good squash bug repellant. I also read that it repels the asparagus beetle. I have tansy, the asparagus beetle and the squash bug. But who knows, maybe I’d have more of the bugs if I didn’t have the tansy. I do manage to keep the bugs under control.
A Great Weapon if they fit Your Life Style – Guinea Hens
People who have Guineas say they have no bugs or very few anyway. They’re much less destructive in a garden than chickens. (Chickens will eat your veggies.) They’re not practical for me to own, but I always wish I could rent a few during the squash bug season.
The tachinid fly is a natural predator I know I have in my garden because it takes care of any Tomato Hornworms that happen along. I see the eggs in what few worms I have in my garden.
I’ve read that it’s a natural enemy of the squash bug as well. And maybe it gets some squash bugs in my garden before I get them, but I’ll never know for sure.
One thing I’ll do this year to increase the chances of the tachinid fly being able to lay its eggs on squash bugs is to plant buckwheat amongst the squash. The tachnid fly can dine on the nectar of the buckwheat bloom and then lay their eggs on the squash bugs. I’ll sow a little patch every week or two close to the squash.
Chemicals for Organic Gardens – The Pros and Cons
All chemicals — even those approved for use in Organic Gardens — need to be used with caution, thought, planning, and care. Keep in mind there is nothing inherently “safe” about naturally occurring poisons.
This is natural pesticide that is derived from flowers. Pyrethrum affects the nervous systems of insects and disrupts normal functioning. It does not kill instantly.
It breaks down quickly – especially in sunlight — and does not persist in the environment.
If used correctly they are considered safe. Inhaling them can cause chest pain, shortness of breath, coughing, and wheezing. Contact with skin can cause redness, irritation , itching and blisters. Pyrethrins are considered the lest poisonous insecticides to cat, dogs, other household mammals, and backyard wildlife. Some gardeners won’t use pyrethrins because they find it toxic to their cats.
Safer makes a Tomato and Vegetable Insect Killer that combines pyrethrins and potassium salts of fatty acids and kills on contact. The potassium salts weaken the insects protective outer shell, while the pyrethrins attack the nervous system.
Neem Oil –Some gardeners swear by it and say they have no squash bugs at all. Others say it’s only somewhat effective. Some gardeners spray twice a year; others spray every two weeks. You’ll still have to patrol for eggs. And to insure a better degree of control you’ll want to continue hand-picking and killing.
I think I would have been tempted to use Neem Oil had I not known certain things about it. Neem is systemic: It enters the plant via the roots and passes through the tissues of the plant. You can pour it on the soil or spray it on your plant and the plant will absorb it. Some insects like aphids who can’t penetrate the leaf deep enough to get a dose of neem — remain unharmed. Squash bugs – that suck all the fluids from the leaf — should get a good dose of neem. That’s the main way Neem Oil kills insects.
Although Neem Oil is — for the most part — considered safe for humans I don’t think I want to take it into my body as part of the food I grow.
One gardener used it for a while — and although effective on the squash bugs — he tasted the neem after a while. That doesn’t appeal to me at all!
Neem – is an oil — thus, it also suffocates insects. It coats the bugs and they can’t breath. It can also kill pollinators and beneficials this way. Beneficials and pollinators are most active during the day, so spraying in the evening would do less harm to the good guys. Once the spray dries, it won’t harm the insects who don’t ingest the plant or it’s fluids.
Safer makes a product, End All, with pyrethrin, neem, and soap. It kills stink bugs and squash bugs. Since it has soap — I would advise caution about spraying on the plant itself since soap can harm plants as mentioned earlier.
I would not recommend using Rotenone although it’s approved for Organic Gardens. If you decide to use it, I hope you will exercise due diligence in researching it.
It comes as a powder or concentrate liquid. In insects and fish it causes paralysis and inhibits oxygen from being taken in by cells.
It is toxic to humans and other mammals. It breaks down in about a week or less, especially when exposed to direct sunlight. Wear protective covering and latex or rubber gloves. Do not spray when it’s windy. Do not inhale as inhalation is said to be even more toxic than ingestion.
A Suggestion on how to use Chemicals approved for Organic Gardens
- Neem or Pyrethrums might be used on trap crops some distance from your garden. This form of trap cropping can be very successful if you have your garden’s squash plants covered with row cover fabric as discussed previously.
- Pyrethrums might be used at the end of the season when you are killing off bugs on plants that are no longer producing.
A Comment on so-called Resistant Varieties
From time to time you’ll see articles about varieties of squash that may be resistant to the squash bug. I’m not sure that one exists — but it might.
I do know that many people who write “articles” about or for gardeners are not gardeners. Nor are they knowledgeable in any garden matters. They take the information that is “out there” and rewrite it and give information they feel is correct, but may not be. I knew a woman once who made her living regurgitating words found in research — through eyes that were totally uninformed in the field she was writing about.
Over the years I have come across so many articles that say this and that variety of squash is resistant to the squash bug — when in fact they truth of the matter is — the variety is resistant to the Squash Vine Borer (usually because of its thick stem). And is in no way resistant to the squash bug. This is so prevalent that I’ve become skeptical about any article on the subject.
In spite of all that, I found myself ordering the seed for Zucchetta which is suppose to be resistant to the squash bug. Zucchetta can be grown on a strong trellis and is a vigorous grower. It’s said to be somewhat firmer than regular zucchini, but mild and delicious. (I got my seed from Pinetree Garden Seeds.)
Bottom Line: If you order something that is suppose to be squash bug resistant — don’t get too excited about it until you’ve grown it.
Hopefully, I’ve given you some information you didn’t already have and more tactics to enable you to win your war with squash bugs.
Wishing you a great harvest of cucurbits!
Organic Gardening is easy, effective, efficient —- and it’s a lot healthier.
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