Flea beetles are some of the smallest beetles known and the moniker “flea” is merely in reference to their flea-like jumping habits as they hop from host plant to host plant. An infestation is easy to identify because flea beetles look exactly like their larger ground beetle relatives, complete with their classic black metallic sheen and scarab-shaped bodies. Flea beetles are winged insects and strong fliers despite being well-known for their powerfully over-sized hind legs capable of catapulting them across the garden. When compared to more ravenous pests that feed directly on foliage like the Japanese beetle or grasshoppers, flea beetles can be one of the more forgiving infestations. The small and scattered “shot holes” created by flea beetles’ chewing habits are not nearly as aggressive as the “skeleton” feeding habits of their invasive relative, the Japanese beetle.
Facts About Flea Beetles
- Flea Beetle Distribution: 6,000 species of winged flea beetles naturalized all over the world
- Flea Beetle Host Plants: Spinach, lettuce, broccoli, cabbage, radish, potato, tomato, fruiting trees
- Flea Beetle Lifespan: 5-6 weeks
- Flea Beetle Eggs Laid per Lifetime: ~80-100
- Flea Beetle Removal: Sticky traps, dish soap spray, talcum powder, pyrethrin, row covers
- Flea Beetle Predators: Birds, braconid wasp, tachinid fly, lacewing
- Most Common Flea Beetle in North America: Spinach Flea Beetle (Disonycha xanthomelas)
What Do Flea Beetles Look Like?
Flea beetles look exactly like they sound; miniaturized beetles capable of jumping from host-to-host just like a common flea. Some species of flea beetle are striped, multitone, or lightly tan, but the overwhelmingly majority found in the home garden will all share the glossy black sheen, scarab body, and smooth hard shell of much larger beetles. Garden flea beetles have a classic matte black anatomy while another swarming beetle, the Japanese beetle, is known for its stunning green and purple iridescence. Although winged and able to fly like the Japanese beetle, flea beetles are known to rely more heavily on their powerful, over-sized legs that enable them to jump from plant-to-plant like grasshoppers.
Flea Beetle Damage
While a flea beetle infestation can still be a damaging nuisance in the garden, it is one of the more forgiving infestations since most established plants are able to recover without much effort. Unlike the ravenous Japanese beetle which can quickly “skeletonize” an entire host plant overnight, flea beetles generally do not feed as aggressively and merely leave behind small “shotholes” in the leaves. When compared to other leaf eaters and pests that feed directly, plants damaged by flea beetles can be salvaged more times than not, but there are some cruciferous flea beetles just as capable of “skeletonizing” hosts as the Japanese beetle. Fruits may be too thick for flea beetles to consume whole, but the scarring and damage left behind will leave the fruit too unappealing for sale or consumption.
What Do Flea Beetles Eat?
Each of the 6,000+ species of flea beetle have a fairly specific diet and preference of host plants, while the striped flea beetle is known to widely feed on just about anything in the garden. The spinach flea beetle, crucifer flea beetle, and striped flea beetle are among the most extensive species found in North America and, between just the three, are known to infest nearly any leafy green, root vegetable, brassica, and nightshade crop such as tomato, pepper, and, eggplant. Root crops such potato, radish, and turnip are especially susceptible to flea beetle infestation in nearly any part of the world. Flea beetles feed on many of the same crops as grasshoppers, snails, and Japanese beetles, making them difficult to identify solely by their diet and feeding habits.
Flea Beetle Eggs
Flea beetle eggs can be difficult to spot with the naked eye because, with more than 6,000 species, each one will lay their eggs in a different place in the garden. Adults lay their eggs just about anywhere that is safe or advantageous as opposed to most insects that routinely lay their eggs in the same place, generally on the underside of leaves. Many flea beetles lay their eggs in the soil, similar to ground beetles, so that the emerging larvae can immediately feed on the roots and softer foliage. Nests can be found within the top ½” of soil and can be removed simply by tilling. Flea beetle eggs laid on stems and leaves will closely resemble that of Japanese beetle eggs; elliptical, slightly translucent, and similar to a chicken egg.
How To Get Rid of Flea Beetles
Flea beetles are small enough that they can be treated like any number of pests when needing removal from the garden. Like most insects, one of the most effective methods is to spray the infestation with organic pyrethrin or a dish or castile soap solution, usually one tablespoon to every ¼ gallon of water. A high pressure hose is usually effective against most pests, especially on established plants, but can be tricky against flea beetles because they will flutter away as soon as they’re disturbed, likely before much of the infestation is hosed off. A light dusting of unscented talcum powder on your crops has been proven to not only repel flea beetles but to help prevent future infestations. Row covers can require a little patience to manage throughout the season but, to those gardeners willing to try, usually are able to keep the pests from their garden early on in the year.