Flea beetles, or Alticini in scientific terms, are pesky, shiny little beetles that come in a variety of colors. But they’re all potentially disastrous for your crops—if left unchecked, they can destroy the roots and foliage of a variety of plants in no time. They’re most dangerous early in the season, as mature plants are better equipped to survive an infestation.
The best way to identify the source of your plant woes is a flea beetle is to examine the damage to the leaves of your plant. Are the holes in the leaves circular? If the damage is in an advanced stage, do the holes create a “lacey” appearance in the leaves? If so, chances are good that you have a flea beetle problem.
Of course, spotting a flea beetle is another fool-proof sign. Unfortunately, they come in a variety of colors—black, blue, and spotted, to name a few—so there’s no set checklist of traits. However, they are often shiny, and if their behavior fits their name, you probably have flea beetles. Yes, they hop—or flee—like fleas when disturbed.
Flea beetles are more than just hole-boring pests. They can ruin a young crop in large numbers. But the worst part about flea beetles is that they often carry diseases, which they spread to the plants they eat. Blight and other bacterial plant plagues often begin with unwanted beetle visitors, so combatting these pests as swiftly as possible is important.
The best way to save your crop from these creepy-crawly pests is to deter them from invading in the first place.
The first thing you should do, if you don’t already, is till your soil in the spring before planting. This will disrupt and illuminate any overwintering flea beetles.
Planting “flea beetle traps”, or their favorite crops, can be a bit risky: done right, they can keep the flea beetles away from your favorite crops by sacrificing your deterrent plants. Done wrong, it can attract flea beetles that otherwise wouldn’t have come, and you could lose your crop anyway. That said, if you want to lure the flea beetles away from your plants, try:
With any luck, they’ll be so occupied with those plants that they forget about your focal crops, like greens and potatoes.
You can also companion plant to deter flea beetles, which tends to be a more successful approach. Try planting these plants near the crops you want to protect:
These methods will do you little good if you have an active flea beetle population. In that case, it’s time for damage control.
There are plenty of ways to combat flea beetles that don’t involve pesticides.
This product is simple but effective: It’s an algae-rich soil that is deadly to most insects, including flea beetles. Dust your plants with it (it’s safe for humans) or sprinkle it around your plants to control or eliminate flea beetle populations.
If your flea beetle population is small and more pesky than destructive, try using sticky traps. The same ones that you hang inside to catch flies can be used between plants to trap beetles as they travel from plant to plant. This is unlikely to help when your flea beetle problem is severe.
There are also several conventional or non-organic methods that do involve some modern chemistry.
As with many pests, soap is poisonous to flea beetles, so spraying a soap and water solution (often called insecticidal soap) on your plants can help control flea beetle populations. Many people use dish soap successfully, and some add a small amount of alcohol to the solution.
Generally, flea beetles aren’t so unbeatable that they require heavy-duty pesticides to defeat. But if yours are or if you just don’t have the time for less invasive treatments, pesticides are an effective option. Use an insecticide indicated for your specific plant at the beginning of the season for best results.