Pest

Flea beetles

Tiny jumping beetles that pepper young leaves with small round holes, worst on seedlings in spring.

What you'll see

• Many tiny round holes or pits in the leaves, like a shotgun blast, mainly on young plants.
• Shiny black, bronze or striped beetles under 1/10 inch (2.5 mm) long that jump like fleas when disturbed.
• Worst on eggplant, radishes, turnips and the cabbage family in hot, dry spring weather.

Why it happens

Adult beetles spend the winter in weeds and debris and feed on tender leaves as soon as plants come up. Their larvae feed on roots, usually without much harm.

How to fix it

1. Cover seedlings and new transplants with fine insect mesh or row cover, sealed at the edges.
2. Keep plants watered and growing fast; most outgrow the damage once past the seedling stage.
3. Tolerate light damage on larger plants; it rarely affects the harvest.

Keep it from coming back

• Clear weeds and plant debris in autumn, where the adults spend the winter.
• Plant out when warm weather lets young plants grow away quickly.
• Check susceptible crops often from spring onward.

Sources

• UC IPM: Flea beetles
• RHS: Flea beetles on brassicas and allied plants
• University of Maryland Extension: Flea beetles on vegetables

General guidance, not a diagnosis. For valuable, edible or outdoor crops, check with a local extension service or plant expert. Use any product exactly as its label says, and keep children and pets away while it dries.