Flea Beetles
TreatablePest · spreads to other plants
Flea beetle damage is unmistakable: a leaf peppered with small round holes. On an established plant this is cosmetic, but on newly transplanted seedlings a heavy attack can stunt or kill them, so timing determines whether it matters.
What it looks like
Dozens of tiny round holes through the leaf, as though it had been hit with birdshot. The beetles are minute, dark and shiny, and jump like fleas when disturbed — which is usually all you see of them.
How to confirm it
- Many small round shot-holes rather than a few large ones.
- Tiny dark beetles that jump when the plant is disturbed.
- Worst on young transplants in late spring.
- Damage concentrated on the upper, newer leaves.
What to do
- 1On an established plant, tolerate it. The damage looks worse than it is.
- 2Protect seedlings with row cover until they are growing strongly.
- 3Yellow or white sticky traps reduce numbers around a bed.
What it gets confused with
One observation settles each of these.
Slug holes are large and smooth-edged with slime; flea beetle holes are tiny, round and numerous.
Preventing it next time
- Transplant slightly larger, well-hardened seedlings that can outgrow the damage.
- Cover new plantings for the first two to three weeks.
Plants affected
Check these two things first
- Push a finger into the soil, two knuckles deep. Wet soil plus a wilting plant means too much water, not too little — and it is the commonest reason a plant is dying. Dry soil plus crisp leaves means the opposite. The leaves look nearly identical either way, so the soil is what tells you.
- Turn a damaged leaf over. Half of all diagnoses live on the underside: fuzz means downy mildew, fine webbing means spider mites, clusters of insects mean aphids. Nothing on the top of a leaf is as informative.
Most garden problems are cosmetic and resolve without treatment. Reach for a spray last, not first.