Tiny invasive little pests that love to munch on garden crops, flea beetles feed on the leaves, roots, and tubers of plants in the Brassicaceae and Solanaceae families.
They choose their host plants by smell as well as by sight. A flea beetle infestation can totally destroy your vegetable garden. Therefore, exploring ways to get rid of them should be your main priority.
Flea beetles are from the Chrysomelidae family. They go through four stages in their lives: egg, larvae, pupae, and adult . They are equally damaging in both larvae and adult stages.
Adults range in size from 1/16 to 1/4 of an inch, and in color from dark brown to bronze to black with several species metallic green, striped-looking, or even blue.
They lay eggs in early spring around the roots of the host plant. The eggs hatch 10 days later, and the larvae go underground to eat and grow.
After hatching in 21 to 35 days, the beetle larvae make cocoons and pupate for about 7-10 days before turning into mature beetles. The adults can both jump and fly.
How to Get Rid of Flea Beetles Naturally
Here are some natural and organic home remedies and tips that work.
1. Neem Oil
This natural insecticide is one of the best ways to get rid of flea beetles organically.
Neem oil repels and deters most insects by disrupting the feeding abilities of the adults and the eating ability and growth of the larvae.
The oil also masks the scent of your crop, repelling the adult bugs. The treatment helps to prevent plant diseases as well.
2. Insecticidal Soap
Made from water, vegetable oil (olive oil or canola), and pure organic liquid soap, this potent soapy water solution kills flea beetles and takes care of most pest problems.
For the recipe, combine 5 tablespoons of liquid soap with one cup of oil in a gallon of water. Shake well and spray directly onto the beetles.
Moreover, the solution will give your plant a nasty taste that will cause them to go elsewhere. Besides, it will eventually kill them if they meddle too much in it.
3. Companion Planting
Using other plants to help disguise or plant along your prized crops will disrupt their reasoning ability.
Among the many plants that repel flea beetles, you can use dill, catnip, mint, basil, and marigolds to mask both scent and sight of the target plants.
4. Till Soil
Keeping the soil tilled at wintertime will keep the adults dormant for the season. They won’t have the freedom to overwinter in the soil.
Consequently, they will freeze when exposed to the cold. Doing this right after harvest but before fall will kill any larvae.
5. Trap Crops
These are sacrificial plants planted in rows between your crops or on the edges of your garden.
The critters love sunflowers, radishes, and nasturtium. Therefore, planting these will attract them, drawing them away from your vegetables.
6. Sticky Traps
These are mainly utilized to help with identifying an infestation than to prevent one. While man-made, sticky traps are considered environmentally friendly.
Surround your garden with it. Keep in mind, however, that these traps can also catch other useful insects and bugs including bees and butterflies.
Clover, as well as other living mulch, can help disguise your main crops, making it harder for them to identify the real thing.
Non-living such as barley straw interferes with the egg-laying process because the eggs need the soil to incubate and hatch properly.
However, it is vital that you remove mulches at the end of the growing season to keep the adults from overwintering in them.
8. Beauveria bassiana
Beauveria bassiana is an organic flea beetle control remedy .
It doesn’t need to be consumed by them either. Just being touched by the spores will sick the beetles so badly, they will die eventually.
After they die, the fungus will cover their bodies in a layer of mold creating more spores — a perfect pest deterrent.
If you get it from a store to put on your garden yourself, be sure to wear protective clothing and follow the instructions carefully.
9. Coffee Grounds
Using coffee grounds for black beetles in the garden is a popular remedy among gardeners, but you should be careful which plants you put them around.
While they’re a great natural fertilizer, they have certain chemicals that will adversely affect some plants.
These same chemicals are toxic to the critters in the larvae stage. Having the grounds spread out over soil under the host plants also messes with the adult egg-laying.
10. Diatomaceous Earth
This is a white powder made from fossilized shells of sea creatures.
The powered version of the crushed shells is fatal to most pests. It tears apart soft-bodied insects like flea beetle larvae, killing them.
Spread it liberally around the base of plants. However, reapply after heavy watering or after there’s rainfall. It also works great to get rid of flea beetles in the house.
11. Row Covers
This is actually a man-made deterrent but it is environmentally friendly.
Install row covers over the rows in early spring and before it gets warm enough for the adults to emerge. However, make sure you remove them when the plants start to flower, or your pollinators will have less to feed on.
12. Predators and Parasitic Wasps
Certain bug predators, like the rough stink bug (not to be confused with its pest relatives, the green and brown marmorated stink bugs), feed on beetles both in both stages.
The braconid is another species of wasps that enjoy laying eggs on adult beetles.
With some research, you can find out which predatory bugs and parasitic wasps are native to your area, as well as how to attract them.
13. Beneficial Nematodes
These fantastic microscopic little roundworms go after both the larvae and adults.
Beneficial nematodes enter their bodies and use them as hosts for themselves and their young. They will remain in the beetle until it dies and then, search out another victim.
14. Control Weeds
Removing weeds and clearing them out when crop season is over will prevent adults from overwintering in the garden and surrounding landscape.
This means not just pulling them, but also throwing them away far from your garden.
15. Kaolin Clay
Used in its powder form, this versatile white clay will help mask the scent of the plants that these black beetles love.
Kaolin clay can be used with water to form a spray or it can be sprinkled on the plants.
Flea Beetle Larvae Identification
These tiny fat worms are voracious eaters and just as destructive as the adults. They hatch from eggs having a white appearance with brown heads and tiny legs.
They range in size from ⅛ to ⅓ of an inch in size. The larvae hide under host plants as soon as it is hatched, and it will eat until it’s time for them to pupate.
If they devour the host plant, they will move on to another plant, and they find it more by scent than by sight.
Flea beetles are a type of leaf beetle. They are extremely dangerous in both larvae and adult stages, attacking both ends of the host plant. Adults feed on leaves while the larvae go after tubers and roots.
Adults cause shot-holing damage: holes made in a shotgun pattern or a loose “lace” pattern on the leaves. If they are bothered while eating, they will jump away and return later to continue.
Larvae mine into tubers and roots making holes and grooves in the flesh. They are so minute they can’t be removed once they’re dug in.
Young plants, as well as those newly transplanted, are so fragile they tend to die from the damage. Mature plants are better able to withstand it and can grow back.
On top of the physical damage imposed, they also help spread wilt and blight bacterial diseases while denuding your crops.
As mentioned earlier, the two plant families on which they mainly feed include:
- The Brassicaceae aka Cruciferae, mustards, and cabbage, contain broad-leafed plants. These include cabbage, arugula, spinach, bok choy, broccoli, kale, and root vegetables such as turnips, eggplant, radishes, and horseradish.
- The Solanaceae aka nightshade and potato contains flowering plants with tubers such as potatoes, and tasty crops like tomatillos, peppers, and Cape gooseberry.
- The tomato flea beetle goes after its namesake.
They also eat lettuce.
This small shiny black beetle is among the worst insect pests a gardener can face. The best way to get rid of them is to avoid getting them in the first place.
However, if you do get an infestation, try the above natural remedies. They are environmentally friendly, and your plants will thank you.