All you need to know about the flea beetles in your garden
Their tiny size and jumping movements give these beetles their name. As adults, they riddle plant leaves with small holes, leaving the foliage dry and desiccated. They are especially fond of seedlings and can consume entire plants before you’re aware of their presence. To determine if flea beetles are present, place a white card on the ground among the plants or on a lawn; the pests are attracted to white, and if they’re near you’ll soon see them jumping on the card’s surface. The white larvae feed on roots, including root crops such as potatoes. They’re small, but you can find them by probing the soil.
To control flea beetles, keep the garden clear of plant debris that could serve as overwintering sites for adult beetles. Till the soil in fall to expose grubs. Parasitic nematodes will control grubs underground. Pyrethrin may help control adults.
Chemical controls effective against adult beetles include chlorpyrifos and diazinon.