Diatomaceous earth is one of the easiest ways to get rid of flea beetles on your plants. Simply sprinkle a light dusting of food-grade DE over your plants and on the soil around them. This non-toxic powder will kill the beetles and deter new ones from coming onto your plants.
Spraying plant leaves with neem oil can get rid of flea beetles and discourage them from feeding on the leaves. It also interferes with insects' ability to reproduce slowing down the lifecycles.
Insecticidal soaps work well to kill flea beetles on your plants. However, it has to make direct contact to work. It does leave a taste on the leaves that most garden pests dislike.
Yellow sticky traps are another non-toxic way to control flea beetles. Place a few traps in between your plants to catch them when they jump from plant to plant.
How To Prevent Flea Beetles
Flea beetles can be a worse pest in the early spring when they have little to feed on naturally. Try to delay your plantings by a few weeks. This gives them wild plants to feed on and your vegetables may be less of a temptation.
As soon as you transplant your vegetables into the garden cover them with a bug netting. Suspend it over the plants with hoops and secure the edges down tightly.
Braconid wasps and machined flies are natural predators of flea beetles. Help encourage them to visit your garden by planting herbs and flowers that they like such as thyme, mint, catnip, dill, chamomile, anise, clover, and marigolds.