Cucumber Beetles

How to Identify and Get Rid of Cucumber Beetles


Cucumber beetles can be easily identified by their black and yellow stripes.

Berea College


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Here are tips on how to identify, control, and get rid of cucumber beetles.

What are Cucumber Beetles?

If you find that the stems of your seedlings are being eaten off, leaves are yellowing and wilting, and holes are appearing, you may have a striped or spotted cucumber beetle. Cucumber beetles are found throughout the US and cause much of the same damage as flea beetles do. They are attracted to cucurbit vegetables, namely cucumbers, squash, pumpkins, and beans.

Often, the beetles leave their hibernating sites early in the season, and feed on seedlings right as they are emerging, often killing them. The larvae feed on the roots of the host plants. Adults will also feed on the leaves, vines, and fruit of plants that survive, often making deep marks in the rind.

They hold another threat too: They can carry bacterial diseases and viruses from plant to plant, such as bacterial wilt and mosaic virus.


How to Identify Cucumber Beetles

Adult striped cucumber beetles are about ¼ inch long and have a yellow and black striped abdomen and a dark colored head and antennae. Spotted cucumber beetles are the same length but have 12 black spots on a yellow abdomen. The larvae are worm-like, white, dark-headed, and have three pairs of legs on the thorax.


Photo Credits: Turner on Flickr Creative Commons. Cucumber beetles can be striped or spotted, and they blend in well with yellow backgrounds.

Cucumber Beetle Damage

Look for holes and yellowing and wilting leaves. Crop yield will be low; and plants will produce yellow and stunted fruits.

Often, the cucumber beetles alone will not kill the plants or cause major damage, but the spread of disease will. Adult cucumber beetles overwinter in weeds, garden debris and woody areas. The diseases they carry can also overwinter internally, and can be passed onto plants the next spring through fecal matter.

Control and Prevention

How to Get Rid of Cucumber Beetles

  • Inspect newly planted cucurbit plants for the presence of this beetle; be watchful when plants are seedlings.
  • Use yellow sticky traps to catch cucumber beetles.
  • Knock beetles to the ground and catch them with a piece of cardboard placed under the plant. Or, use a handheld vaccuum to suck up the beetles. They are very hard to hand pick, but it is easier to hand pick them with yellow gloves coated in petroleum jelly.
  • Cover seedlings with row covers, though you must remove during blossoming time several hours each day to allow pollination.
  • Few insecticides can be used on cucurbit plants because they are very sensitive. They would need to be used when plants are beginning to emerge through the soil. Please contact your local cooperative extension for a list of approved insecticides for your area.
  • Folk advice from The 1963 Old Farmer’s Almanac states that nasturtiums and wood ashes are effective against cucumber beetles.

identify-striped-cucumber-beetle.jpg on Flickr Creative Commons. Use the above tips to keep the striped cucumber beetle from wreaking havoc in your garden.

Prevent Cucumber Beetles

  • If you till your garden in the late fall, you will expose cucumber beetles hiding there to harsh winter conditions and reduce their populations next year. Tilling has the added benefit of making the soil easier to work in the spring.
  • Where cucumber beetles are a problem, let the beetles come out of hiding and plant late. They have a knack for finding vulnerable seedlings. When yours are up and growing, the cucumber beetles will be gone, fooled into thinking you don’t have any cucumbers in your garden.
  • Natural predators include beneficial insects like braconid wasps, some nematodes, and soldier beetles.
  • See more natural remedies for controlling cucumber beetles on our page for getting rid of pests naturally.
  • Companion planting can be helpful to keep pests away. Plant tansy to repel cucumber beetles.
  • Once bacterial disease has entered the plant, there’s very little that you can do. If it’s bacterial wilt, you’ll see the leaves dry up and the plant will quickly wilt and die. Take prevention for next year as described above.

Reader Comments

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Black beetles with yellow and white spots

I planted a whole lot of mixed veggies and find that I have some black beetles with yellow and white spots eating what I suspect to be my mustard spinach. Everything else (including normal spinach) is fine. Any ideas what this is and how I can control it without harmful pesticides?

Mustard Spinach

The only real pest mustard spinach is susceptible to is a flea beetle (there are many types, including a spotted species), which is hard to control. Protecting plants with barriers such as a row cover before infestation is the best management strategy. Before putting the garden to bed for the winter, remove all old debris from your infested plants. Since flea beetles overwinter in the soil, try hoeing and cultivating in the early spring to destroy the larvae. Add a thick layer of mulch around young plants to prevent the beetles from jumping up on to the leaves. Place some sticky traps nearby to try to capture those that persist.

I have successfully grown

I have successfully grown cucumbers for the last two years and several different varieties of them. I live in St. Louis MO. I have tried in the past and several times to grow squash, and cantaloupe and watermelon all to no avail.

The pest that made me give up was not the cucumber beetle, it was a beetle that is green with black spots. Apparently they were infecting the plants with the wilt, and the plants would just die in a matter of days. I tried everything to keep them out and off the plants but they won. I no longer plant any of these plants as I was never able to get any produce. There were literally hundreds of them. My yard and garden does not have any trashy areas for them to over winter in.

Since this is not the black and yellow striped cucumber beetle what is it? It is certainly as devastating as the cucumber beetle.

What are these beetles and is there any way to control them?

Your plants were attacked by

  • Your plants were attacked by the spotted cucumber beetle. You can use row covers before the veggies flower to keep them away from the plants. Or you can use organic pyrethrins or organic rotenone on the plants.

I am just finding out about

I am just finding out about these awful beetles and my garden has been established for over a month with my squash and now noticeably my cucumbers being destroyed. Are the few squash I have safe to eat? Or is it safe to say that my garden is contaminated and I need to rid of the plants? :(

Hi Sara, Your squash is safe

Hi Sara,
Your squash is safe to eat. Try some of the remedies mentioned on this page to get rid of the beetles.

I tried the laundry detergent

I tried the laundry detergent for cucumber beetles and it seems to be working. Also added beneficial nematodes the the soil hoping to kill off the larva. So far the beetles seem to be gone. In central Texas and our growing season has already started. On the look out for other pests now.

dish soap works on cucumber beatles

I have potted zucchini on my deck. Cucumber beatles are chewing through the leaves and spreading the zucchini wilt. I tried the dish soap trick and it worked. I put a bowl like a cerial bowl down next to the pots with a couple of drops of dish soap and water. Added a few drops of yellow food coloring for color. Its been down for 2 hrs and I have 5 cucumber beatles floating dead.

Cukes were doing great,

Cukes were doing great, suddenly I noticed a tiny hole in one so I cut it open & there was a small grub looking worm inside, checked others and they also had them. Pulled all plants,SAD, my question is the potting mix also compromised, or can I start again with same potting mix?

These might be pickleworms

These might be pickleworms (Diaphania nitidalis). They are larvae of a moth, and bore holes into cucumbers and other cucurbits. They are a tropical/subtropical insect, and overwinter in southern Florida and southern Texas. However, each season, they can appear as far north as Canada. Depending on the climate, there can be several generations per year. Certain cucumber varieties, such as 'Gemini', are more resistant to pickleworms. Early planting also helps control this pest. Check for tiny worms feeding in flowers and buds; older worms will start to bore into the fruit; stems are sometimes tunneled into as well, causing wilting. Pupae overwinter in weeds or rolled leaves; remove rolled leaves and check for eggs on vines. Some recommend covering your crop with row covers overnight, to block the nocturnal moths from laying eggs on them; remove the covers during the day to allow bee pollination.
For more information, see:
Based on what I can find, it should be OK to re-use your potting mix, as long as all infested vegetation has been removed. If you live north of Florida, the pests will be killed from cold during the winter season.

I had great success with my

I had great success with my first crop of yellow summer squash last year, I planted marigolds around the edges of my garden. I will do both this year; add the liquid detergent 'Gain' and plant the flowers, this will be my first attempt at cucumbers.

Gain detergent to kill pest in garden

what mixture of gain detergent did you use to kill pest in garden or flowers?

Bug problems on my gourds...I

Bug problems on my gourds...I am seeing the cucumber beetle and squash beetle on my gourds. Found several ideas here to try. But, I'm not getting flowers on the Luffa, and on the Bottle neck and Apple gourds, the flowers are drying up and dying or as the little female flower starts showing the hourglass shape, it's drying and dying off. What's going wrong?

When the tiny female fruit

When the tiny female fruit shrivels and dies instead of developing, it's almost always a pollination issue. Do you have bees in the garden? Bees stay away if there are insecticides, rainy days, or extreme weather. You could always hand pollinate the female blooms. Just take the male stamen and brush it against the female in the morning when both blooms are open.

I see no evidence of cucumber

I see no evidence of cucumber beetles or larvae, but the plants grow beautifully for 25-30 days and then the entire plant withers and dies. The root is rotted completely except for some fibrous material which, apparently the pests or fungus cannot digest. Any other possibilities, or any suggestions?

That's unfortunate, Paul. It

That's unfortunate, Paul. It sounds like a wilt, especially if there is no sign of beetles and the plants appear to thrive, until they fail fast. Fulsarium wilt survives in the soil for years. There are no chemical treatment for this; planting resistant varieties is the best advice.
There is also a bacterial wilt that can cause the plant to die off but it is carried in (yes, in) the beetles. They distribute it in excrement and the slow demise begins.

I put a yellow frisbee and a

I put a yellow frisbee and a yellow bowl in my garden with water and dish soap in them and every day I see floating cucumber beetles and other bugs!

Finally I found a solution

Finally I found a solution for cucumbers bugs....dead,,,,, I got this product in USA it called :ECO SMART ORGANIC ISECTICIDE, it is safe.

I was wondering a little more

I was wondering a little more about the flea beetle trick??

thanks for the tips, i

thanks for the tips, i recently say a video of someone using a clove of garlic mixed with about 3 cups of water to liquefy then adding an additional 3 cups and letting it sit for a couple of days to ferment. once fermented mix with water (1 part garlic solution to 10 parts water). just about to make my batch now fingers crossed that it works.

We grow organically and are

We grow organically and are always looking for effective ways of minimizing insect damage and over the years we have learned a few "tricks". Yes we plant the beans late for our area (south shore Nova Scotia)usually around the first week of July and miss the bean beetle cycle. For the cucumber beetle and potato beetle I place glass jars with about an inch of heavily perfumed laundry soap every 10 feet along the rows partially dug in to avoid spillage. Just poke a few holes in the lids for the scent to escape and we no longer spends hours handpicking these beetles off. It really does work. Just add more as needed. We still see the insects around the edge of the garden but the perfume does not allow them to find the plants you are protecting. Fleas beetles...till the soil and seaweed.
Aphids are dealt with by mixing sodium borate (borax) with icing sugar and place in small plastic tubs with holes near the base large enough for ants to get into. Place at the base of your apple trees and other plants affected by them. You will spend a lot less time picking off insects leaving more time to weed. :)
Remember not to mow around your fruit trees leaving your dandelions to bloom and attract the bees till your trees are ready to blossom out, then mow. We also encourage toads by placing inverted clay flower pots here and there. Happy gardening everyone in 2012.

I am going to try this tip. I

I am going to try this tip. I have had trouble growing summer squash as well as cucumbers. I have tried everything on the market and everything I have read this far with no luck.
I have been trying for 23 years. So here goes number 24.
Thanks :)

I have never had the cucumber

I have never had the cucumber beetle before.I bought from a different its invested.Im so upset I will try ypur advise.Im in Nova Scotia.

Debra, The stink bug is the

Debra, The stink bug is the worst enemy of squash. First solution that has worked 100% FOR ME. OUT OF 9 PLANTS THIS YEAR HAVE PICKED AT LEAST 150 LBS. OF ZUCCHINI SQUASH. Two people, one on each side of plant. Take hose and flood stem of plant. They spend their time under the stem root. When they come up for air, squash them. I have killed at least 40 of them this way and none have had time to lay their little red eggs under the leaves.

hi what type of laundry soap

hi what type of laundry soap do you use is it dry or liquid soap please anwser needed asap thank you

I have found a few cucumber

I have found a few cucumber beetles inside blooms. Will this trick drive them away? I was wondering the same thing someone else asked...liquid or dry detergent? want to try right away before I get an infestation!

I was wondering what kind of

I was wondering what kind of detergent you use. How about dryer sheets? Would that work too?

Any strong smelling laundry

Any strong smelling laundry soap will do. You can try dryer sheets.

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