Flea Beetles

How to Identify and Get Rid of Flea Beetles

control-flea-beetles

Flea beetles can be very destructive to a wide variety of plants, so be sure to take preventative measures.

Greg Bryant, North Carolina State University

Having trouble with flea beetles in your garden? Here are tips on how to identify, control, and get rid of flea beetles so that they stop eating your crops!

What Are Flea Beetles?

Flea beetles are small, shiny-coated beetles with large rear legs, which allow them to jump like fleas when threatened (the source of their name!).

There are many species of flea beetles. Some species attack a wide range of plants, while others target only certain plant families. In the garden, a number of vegetable crops are susceptible to these pests, particularly those in the Brassica family, like broccoli, cabbage, kale, radishes, and turnips, as well as Nightshades such as tomatoes, peppers, and eggplants.

Identification

How to Identify Flea Beetles

Given that there are so many species of flea beetles, they vary in appearance quite a bit. Colors range from black to tan, with other, brighter colors mixed in, and the beetles may have a solid, striped, or spotted pattern depending on the species.

To identify flea beetles, it’s easier to look for signs of their damage (described below) than for the beetles themselves. At only 1/16 of an inch in length, flea beetles are very tiny and will quickly spring away—like fleas—if they see you approach!

When Do Flea Beetles Appear?

Adult flea beetles overwinter in brush and wooded areas. Adults pose the biggest threat early in the planting season as they are emerging, typically when outdoor temperatures reach 50ºF (10°C). At this time, seedlings are being planted, too, and they are most susceptible to beetle damage.

Eggs are laid at the base of plant stems in early summer after the spring feeding period, and larvae feed at the roots.

Flea Beetle Damage

Adult beetles feed on foliage, producing “shotholes” in the leaves. Look out for these holes especially on young seedlings, where damage is most rapid and will cause the most harm. The holes they make will be round and can quickly damage leafy greens. New leaves are usually damaged first, and they will have a lacy appearance.

Flea beetles usually don’t cause fatal damage to established plants because the leaves are already large enough to survive with a few holes. The real danger is that the beetles can spread bacterial diseases, such as wilt and blight, from plant to plant. Therefore, they are still important to consider a pest.

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Photo Credit: University of California White Mountain Research Center. Flea beetles can cause leaves to appear lacy after they’ve caused a lot of damage.

Control and Prevention

How to Get Rid of Flea Beetles

  • Try this homemade spray to control flea beetles: 2 cups rubbing alcohol, 5 cups water, and 1 tablespoon liquid soap. Test out the mixture on a leaf of the plant, let it sit overnight, then spray the rest of the plant if you don’t notice any adverse effects. Spray the mixture on the foliage of garden plants that are susceptible to these pests.
  • Dusting your plants with plain talcum powder repels flea beetles on tomatoes, potatoes, peppers, and other plants.
  • Use white sticky traps to capture flea beetles as they jump.
  • Insecticides may be used early in the season, but are generally unnecessary in the control of flea beetles on adult plants. Be extra diligent if your soil has history of bacterial diseases. Please contact your local nursery or cooperative extension for further advice.

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Photo Credit: Jeff Hahn, University of Minnesota Extension. If you didn’t take preventative measures, it might be impossible to stop the flea beetle damage.

How to Prevent Flea Beetles

  • In the spring, emerging flea beetles will be waiting to feast on your garden. Cut off their food supply by delaying transplanting or planting by a couple weeks if possible.
  • In the fall, till the garden to unearth any hiding flea beetles. This will also make soil easier to work the next spring.
  • Row covers may be successful at keeping these pests out, as long as they are completely sealed. They should be used immediately after transplanting, so the pests do not have time to find the plant.
  • Flea beetles are repelled by catnip and basil. They are attracted by nasturtium and radishes. You can plant these as traps for the flea beetles so that they do not attack other more valuable plants.
  • Check out these tips to attract beneficial insects, which will prey on flea beetles.

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Reader Comments

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Flea beetles

Do they live indoors

Cucumber Beetles

The Editors's picture

No, cucumber beetles are not generally a problem indoors, unless they’ve hitchhiked on your clothing or a plant that you brought inside. Even then, they are unlikely to reproduce indoors.

hi, We have some mustard

hi, We have some mustard grown here, unfortunately, flea beetle left so many holes on them. After that, I found that the hole edge get purple, so it looks like there are so many purple holes on mustard. It's different from holes flea beetle left on other vegetables. Do you know the reason for this?

Purple Holes

The Editors's picture

Some varieties of mustard naturally have a purplish tinge to the leaves, so our guess would be that the tissue immediately surrounding the holes in the leaves starts to die and lose its green chlorophyll, leaving the dark color around the holes. On the other hand, a fungal disease called alternaria leaf spot may cause purplish-black lesions in leaves. Search google for an image of alternaria leaf spot and see if it matches what you’re seeing. If alternaria leaf spot is the culprit, remove heavily affected leaves and avoid planting mustard in the same spot next year.

Any chance of damage to birds that forage in the garden?

I am just wondering whether the dead beetles sprayed with this mixture pose any danger to songbirds foraging in the garden?

Bird Safety

The Editors's picture

Hi Kathleen,
The amount on the insects should be small enough that there will be no adverse effects to birds. 

Flea beetle control

Can I make a spray with 100% alcohol? Maybe only 1shot to 5cups water?? Or would coffee grounds be better on the ground with flour sprinkled on the plants?

Flea beetle spray

How often should you use the spray?

get rid of flea beetles

The Editors's picture

Hi, Meredith. You can apply as often as once a week. Good luck!

Flea Beetle Indoors

Do you have any suggestions for eradicating flea beetle indoors? I am a florist who uses locally grown flowers and these bugs seem to have setup camp in the drop ceiling of my studio. Not sure what they are surviving on.

flea beetles on tomato leaves

I sprayed one leaf with the alcohol/water/liquid mixture yesterday. The leaf turned brown and curled. Any other ideas? Maybe less alcohol?

Reduce Alcohol

The Editors's picture

Yes, dilute the mixture with more water. Try doubling the amount of water and testing again.

Alder flea beetles

My alder trees get these guys every year. I tried to wrap fly paper around the trunks this year and it appears to have helped a bit, but do they fly up from the ground into the upper areas of the trees or do they migrate up the trunks into the leaves? If they travel up the trunk, sticky tape would seem to be a possibility for controlling them. Any ideas? I lost an ancient singleton alder years ago from these bugs. If left alone, they can do significant damage.

eliminating flea beetles

The Editors's picture

We turned to the experts for help with this one, Roderineo, especially because you have them in your trees. Because the fleas seem to overwinter in the leaf and plant residue at the base of the trees (see the following), you might consider cleaning up those areas.

• Here’s a forest management site that describes their life cycle: https://www.fs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb5186816.pdf

• Here’s the Oregon Cooperative Extension: http://oregonstate.edu/dept/nurspest/alder%20flea%20beetle.htm

• Britain’s Royal Horticultural Society has very good information; here’s what they say about this: https://www.rhs.org.uk/advice/profile?PID=850

We hope this helps!

turnips

what is it when I grow turnip the get holes all through them underground in the little turnips ive never seen any bugs could it be cutworms and how do I get rid of them?

turnip holes

The Editors's picture

Hi, Ken, It could be cabbage maggots, which are the larvae of the cabbage root fly. They love turnips. The most efficient preventative is to use floating row cover (light-weight “cloth”) in such a way that it creates a tunnel and is secued at ground level on all sides (and ends). The cover can touch the plants, but should be loose enough as to not constrict growth of the plant. We hope this helps!

tomato insect

I'm not sure that I have flea beetles because they don't try to jump away (or flee.. yuk) when pulled off my tomato plants. They tend to cling to the leaf. They are dark black, a tad shiny and shaped like a football with a somewhat rounded tail and a bit more pointed head. They are very small, 1/16" or smaller. They do have wings, small antenna and appear to have eight legs. Aside from that, they eat small elongated holes in the leaf and may have been responsible for yellowing of the plant especially on the bottom 1/4 of the plant. However, plant food seems to have helped with the yellowing. I applied Sevin spray this morning and hope that helps. Are these flea beetle and what else can I try if the spray doesn't help?

flea beetles

How large are the "parts" of alcohol and water? You specify 1 Tablespoon liquid soap, but not the amount of alcohol and water to which it is added.

flea beetle spray

The Editors's picture

You’re right, Linda. It seems we’ve mixed apples and oranges here. We suggest mixing 5 cups water with 2 cups alcohol plus 1 tablespoon of liquid soap.

Alcohol concentration for flea beetle spray

I'm thinking ahead to the next growing season and how best to combat the flea beetles that always destroy my Brassicas. I rent a plot in a community garden, so I don't have as many options as I would on my own land. In looking at your alcohol spray, it seems a little heavy on the alcohol, and I wonder if it might burn young plants. Is there a minimum ratio of alcohol to water that would still be effective against these pests, or is it just trial and error? Also, I have heard that vinegar can help. Do you have any thoughts on this and what might be a good ratio of vinegar to water to deter the beetles but not damage the plants? Thanks.

alcohol and vinegar sprays

The Editors's picture

I’m not sure if a study has been done as to the minimum ratio of alcohol/water plus soap for effectiveness. However, you are right to be concerned about burning plants. With alcohol sprays, always test a solution on a small area before spraying an entire plant or crop; some plants may be more sensitive than others. You might try a solution with a small percentage of alcohol to water and work up to determine the minimum you can use and still have it be effective. As to vinegar, same precautions. One must be very careful about proportions, or as you have read, the vinegar’s acetic acid can kill plants (at higher concentrations, vinegar is used as an herbicide). Some sources suggest avoiding using it at all, especially on vegetables or flowers. Others suggest 3 parts water to 1 part vinegar, and only spraying leaves. If you try this route, you might try diluting the solution even further, then testing on a small area first. Hope this helps!

blue flea beetles

We have stacks of blue flea beetles on our land and see them as a blessing. They got on top of the dreaded buzzies and congregate in large clusters on dying vegetation. Our little granddaughter treats them as pets. They are most welcome apart from being beautiful.

Blue beetles

We have these little suckers everywhere on our property. Vegetable garden, strawberry patch and the house garden and natives. Any clues how to treat. Not sure about the rubbing alcohol on food we will be eating. And how to treat such a large area.

The Beetle Blues

The Editors's picture

Hi, Betty: Sorry to hear! It sounds like these might be blue milkweed beetles, which always pose a tricky problem because hosts for them like milkweed and oleander, which you would want to eliminate if nearby, are also beneficial to monarch butterflies and others. The best thing to do is bite the bullet and try to physically remove as many as possible by plucking or even using a handheld battery-operated vac. Another option is an organic insecticide applied very specifically to aggregations of beetles where found. It’s important to try to do this before they lay their eggs, so alacrity is of the essence. Good luck!

Heres another trick to try as well

Take old coffee grounds and about 5 or so drops of hot sauce care not to use much hot sauce as it can burn roots but put that at base of all plants .. For leaves i use flour once a week on all my plants.. The only down side i seen with flour was little dough balls in my yard but they go away in a short period of time after it rains i reapply everything again

Do shining flea beetles bit

Do shining flea beetles bit and we found one in our house but we don't have any plants inside or outside our home

Is there any risk in eating

Is there any risk in eating the plants that were infected with flea beetles? My entire crop of Arugula was infested and now my Brussels sprouts are getting eaten as well. I am also noticing small brown balls where they sprouts are growing. Any advice is appreciated.

WHAT ARE THE CATIPILLARS THAT

WHAT ARE THE CATIPILLARS THAT PUNCH THROUGH THE HUSKS AND INTO THE CORN EAR AND HOW DO YOU PREVENT THIS.
THANKS

The corn earworm is the

The Editors's picture

The corn earworm is the larvae of a tan night-flying moth. Wait 'til the ears start to fill out and put 1 or 2 drops of mineral or vegetable oil on the silks. You can also treat the corn with Bt (Bacillus thuringiensis).

Mineral oil. A few drops into

Mineral oil. A few drops into the silks at top of ear. Works like a charm

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