If you are bothered by little black bugs in your garden, chances are they are flea beetles. The tiny black bugs on plants are quite bothersome and pose a threat to a wide variety of vegetable crops.
In this article, we describe flea beetles and the damage they cause and share advice to help you deal with them.
Why Are These Small Black Bugs Called Flea Beetles?
These pests are not related to fleas in any way, but they do have one similarity.
Like their namesake, these small, shiny black beetles have powerful back legs allowing them to cover a lot of space in a single hop.
Like fleas, these beetles are very small.
At full maturity, they are only about a sixteenth of an inch long.
They tend to congregate in great numbers on plants and hop about wildly when disturbed, so the resemblance to fleas is unmistakable.
Although the bugs are often black, this is not always the case.
They can come in tan or brown, making them look even more like fleas.
In some cases, they are spotted.
It all depends upon the species of flea beetle in question.
What Kind Of Damage Do Flea Beetles Cause?
The damage caused by flea beetles is most evident early in the springtime when they emerge from overwintering in woodlands and brushy areas.
As soon as the temperature hits 50º degrees Fahrenheit (10° C), they awaken from their slumber ready for breakfast.
The adult beetles like to feast on plant leaves, and they are especially fond of tender young leaves.
They will make their way to your new seedlings first, and soon you’ll see “shot-holes” in all your fresh, young leaves.
If left untreated, your young seedlings will look as if they are made of green lace.
This type of predation can kill very young plants.
Later in the growing season, if flea beetles attack mature plants, their damage may be unsightly, but it is unlikely to kill the plant.
The exception to this is flea beetles, like other types of pests, are vectors for illness.
These beetles may carry the bacteria causing blight and wilt from one plant to another.
This can have a seriously detrimental effect on your crops.
To mitigate the potential damage flea beetles may cause, have your soil tested for the presence of bacteria.
This will give you some idea of exactly what harm may come from flea beetle infestation.
Talk with your county extension agent to find out about solutions for any bacterial problems present in your soil.
What Can You Do To Get Rid Of These Little Black Bugs?
Luckily, there are many ways to repel and overcome flea beetles.
Try some of these tips:
1 – Make a natural flea beetle spray by combining five cups of water, two cups of isopropyl alcohol, and a tablespoonful of natural liquid soap, such as Dr. Bronner’s castile soap.
Spray this mixture liberally onto plants infested with flea beetles.
Be sure to test a small area first and wait 24 hours in case of adverse effects.
This mixture will kill the pests on contact, but it does not have residual effects.
2 – Repel flea beetles by dusting your plants with diatomaceous earth or with talcum powder.
Both of these substances are unpleasant to these pests.
Diatomaceous earth will have the effect of killing the beetles (and any other insect it comes in contact with like fungus gnats) by drying out bodily fluids.
3 – Strategically placed sticky traps are effective against flea beetles.
The downside is sticky traps are indiscriminate and will also entrap beneficial insects and even small wildlife such as hummingbirds.
4 – Early in the growing season, you may wish to use insecticides to protect your young plants, but this should be a temporary solution.
It is not usually necessary for flea beetle infestation of mature plants.
What Can You Do To Prevent Flea Beetle Infestation?
1 – Flea beetles will emerge from overwintering when the weather warms up, whether or not there is anything to eat.
Delaying planting for a couple of weeks can deprive them of food and cause them to move on before you get your crops out.
2 – Place row covers over your newly planted crops to keep flea beetles out.
Put the covers in place as soon as you put your seedlings out.
You must take great care to seal the row covers completely because these beetles are very small.
3 – Mix some repellent plants in with your veggies.
Flea beetles hate basil and catnip, so interspersing your veggie rows with these can keep flea beetles away.
As a bonus, basil planted with tomatoes improves the flavor of the tomatoes.
On the downside, catnip attracts and inebriates cats, and drunken cats may be more damaging to your veggies than flea beetles.
4 – At the end of the growing season, after the weather has cooled, till your garden thoroughly to unearth flea beetles in hiding.
Exposing them to cold temperatures will kill them.
A Healthy, Balanced Garden Is Inhospitable To Flea Beetles
Encouraging predatory insects, birds, reptiles, and amphibians to live in your garden is always a good idea for controlling flea beetles and all manner of other insect pests.
Having a healthy population of natural garden helpers can eliminate the need for pesticides.
One of the best natural enemies of flea beetles is the Braconid wasp (Microctonus vittatae).
The mature wasp will kill adult flea beetles.
Additionally, the wasp larvae grow on female flea beetles and stop them from reproducing.
Garden critters such as lizards, geckos, and toads also make short work of these little black insect bugs.