Flea beetles are a common pest for potato growers. These tiny insects can cause major damage to potato plants if left unchecked. Here is a comprehensive guide on identifying, preventing, and controlling flea beetles in potato crops.
What are Flea Beetles?
Flea beetles are small insects, around 1.5 to 2.5 mm in length. They are called “flea beetles” because they can jump, like fleas. There are many species of flea beetles, but the ones that affect potato plants typically have metallic brown or black shells.
The flea beetle life cycle has four stages – egg, larva, pupa, and adult. The larvae live underground and feed on potato roots. The adults live above ground and feed on the leaves, stems, and sometimes the tubers. It is the adult beetles that cause the most visible damage to the plant.
How Do Flea Beetles Damage Potato Plants?
Flea beetles damage potato plants in two ways
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Adults chew small holes in leaves, which can stunt plant growth and reduce photosynthesis if damage is severe. The shot hole appearance of the leaves is characteristic of flea beetle feeding.
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Larvae burrow into tubers, causing tunnels and rough, brown scabbed patches on the potato surface. This makes the potatoes unsuitable for processing or sales.
Young potato plants are most susceptible to flea beetle damage. Mature plants can tolerate more feeding without impact to yield. But heavy infestations at any growth stage can be devastating.
Signs of a Flea Beetle Problem
Check potato leaves regularly for early signs of flea beetles:
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Small round holes chewed in leaves, like buckshot. Look on the undersides of leaves too.
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Jagged edges or a lacelike appearance of leaves.
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Flea beetles present on the plants. These are very small (1-2 mm) insects that jump when disturbed.
Also dig up a few sample tubers to check for tunneling damage. Finding flea beetles or their damage early allows you to take action before populations explode.
Preventing Flea Beetles in Potatoes
The best defense is preventing flea beetles from ever reaching damaging levels in your potato crop:
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Control weeds, especially pigweed, around the field. These provide an early spring food source for emerging beetles.
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Delay planting potatoes if possible until soils warm above 50°F. This is less hospitable for flea beetles.
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Use floating row covers over plants, secured tightly to keep out pests. Remove covers when plants start flowering.
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Intercrop with repellent plants like catnip, radishes, or onions. The strong smells mask potato plants.
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Rotate potato fields annually to interrupt the flea beetle life cycle. Avoid planting in areas downwind from last year’s crop.
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Till under crop debris immediately after harvest to destroy overwintering adult beetles.
Organic Flea Beetle Treatments
If preventive measures fail, there are several organic approaches to controlling flea beetles:
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Insecticidal oils – Products based on neem oil or canola oil kill larvae and repel adult beetles on contact. Coat leaf undersides for best results.
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Diatomaceous earth (DE) – Dust this abrasive powder on plants and soil. It damages the waxy coating on beetle shells, causing dehydration. Reapply after rain or heavy watering.
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Beneficial insects – Predators like braconid wasps and tachinid flies feed on flea beetle larvae in the soil. You can buy them from garden suppliers or attract naturally with flowers.
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Sticky traps – Yellow or blue sticky traps lure adult beetles and capture them before they can feed and reproduce. Place traps near plants around mid-spring.
Conventional Insecticide Options
If organic options prove insufficient, conventional insecticides registered for flea beetles in potatoes include:
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Imidacloprid – A neonicotinoid that is applied at planting, either as a soil drench or seed piece treatment. It is systemic, protecting the whole plant.
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Dinotefuran – Another systemic neonicotinoid that can be used as soil or foliar application. Do not mix with imidacloprid in the same season.
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Lambda-cyhalothrin – A pyrethroid insecticide that can be used as foliar spray on adults. It is fast-acting but has very little residual activity.
Always follow label directions carefully for any insecticide. Be mindful of re-entry intervals and pre-harvest intervals. Proper crop rotation and insect resistance management is critical when using conventional chemicals on potato pests.
Control Flea Beetles Quickly
Left uncontrolled, flea beetle damage reduces potato yield and quality. Scout fields regularly for the first signs of flea beetles. Implement preventative strategies early in the season. At the first sign of damage, use organic treatments like oils and beneficial insects. For severe infestations, targeted insecticide applications may be warranted to avoid major crop losses. With diligent monitoring and timely intervention, flea beetles can be managed for healthy and profitable potato production.
Biology Crucifer flea beetle larva
- Flea beetles live through the winter as adults in leaf litter, hedgerows, windbreaks and wooded areas.
- Adult flea beetles become active in early spring. Depending on the species, females lay single or clusters of eggs in small holes, in roots, soil, or leaves of many vegetables as well as occasionally on flowers and ornamental shrubs and trees.
- Small white larvae hatch from eggs and feed on the roots of the newly planted seedlings.
- Larvae then transform into pupae in the ground. There are usually one to two generations per year.
How to identify flea beetles A black potato flea beetle making holes in a potato leaf
Most adult flea beetles are very small (1/16 –1/8 inch long). An exception is the spinach flea beetle, which is 1/4-inch long.
- Flea beetles can be black, bronze, bluish or brown to metallic gray.
- Some species have stripes.
- All flea beetles have large back legs which they use for jumping, especially when disturbed.
A shiny black crucifer flea beetle making holes in a green leaf
The most common flea beetles in Minnesota:
- Crucifer flea beetle (Phyllotreta cruciferae)
- Striped flea beetle (P. striolata)
- Western black flea beetle (P. pusilla)
- Potato flea beetle (Epitrix cucumeris)
- Spinach flea beetle (Disonycha xanthomelas)
Most flea beetles feed on very specific plants, but the pale-striped flea beetle (Systena blanda) feeds on a variety of plants, like squash, beans, corn, sunflowers, lettuce, potatoes and many weeds.
Tomatoes and Potatoes and Flea Beetles
FAQ
How do I get rid of flea beetles on my potato plants?
Dusting leaves 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.
How do I get rid of flea beetles in my vegetable garden?
Control Flea Beetles
At the first sign of flea beetles in your garden, turn to a trusted pesticide such as Sevin brand for help. Sevin Insect Killer Ready to Use2 kills flea beetles on listed vegetables on contact to help prevent damage to tender seedlings and maturing plants at the first sign of trouble.
How do you get rid of potato beetles?
Recommended treatments are spraying beetles and eggs with soapy water, gently scratching off eggs, sprinkling diatomaceous earth around the plants (only effective when dry), mulching, and allowing ladybugs to eat them. See the resources below for details.
What is the natural enemy of flea beetles?
Natural enemies of flea beetles include Microctonus vittatae (parasitic wasp), entomopathogenic nematodes, white muscadine (fungal pathogen), and generalist predators such as lacewing larvae, adult bigeyed bugs, and damsel bugs. M. vittatae wasps kill flea beetle adults when they emerge after development.
How do you know if a potato plant has a flea beetle?
Flea beetles feed on leaves, creating small holes that give them a “shot-hole” appearance. To identify flea beetle damage, look for small holes in the leaves of your potato plants. You may also notice tiny black beetles jumping around when disturbed.
How do you control flea beetles on potato plants?
To control flea beetles, it’s important to regularly monitor your plants and act promptly if an infestation is detected. Applying insecticides labeled for flea beetle control can help protect your potato plants. Additionally, using floating row covers during planting can prevent flea beetles from reaching your crops.
What eats my potato leaves?
What’s Eating My Potato Leaves? The most common pests that eat potato leaves are the Colorado potato beetle, flea beetles, leafhoppers, snails and slugs, aphids, leaf-eating worms (caterpillars, armyworms and cutworms), deer and rodents.
How do I protect my potato plants from fleas?
Applying insecticides labeled for flea beetle control can help protect your potato plants. Additionally, using floating row covers during planting can prevent flea beetles from reaching your crops. Late blight is a devastating disease caused by a fungus-like organism that affects potato plants.
What plants do flea beetles eat?
The flea beetle (family Chrysomelidae) is a pesky visitor to most gardens. The beetle targets tasty plants in the families Solanaceae (potatoes, tomatoes, eggplant, peppers) and Brassicaceae ( including cole crops: broccoli, kale, cabbage, collards).
How do I know if I have a potato beetle infestation?
Both the adult beetles and their larvae feed on the leaves of potato plants, causing extensive defoliation if not controlled. To identify a Colorado potato beetle infestation, look for adult beetles or their eggs on the undersides of leaves.