Flea Beetles: Tiny Menace in the Vegetable Garden
Flea beetles are a voracious group of early-season pest we battle in vegetable gardens. There are several species of these shiny, oval-shaped 1/10” long beetles, each enjoying their preferred vegetable in the garden. Flea beetle populations are higher following a warm winter, and damage is more severe during hot and dry conditions. The crucifer flea beetle (Phyllotreta cruciferae) affects plants in the Brassicaceae or cabbage family, preferring turnips, mustards, and arugula over those with waxy cuticles, like kale. Adults feed on leaves and stems, leaving small round holes that heal with a silver cast. The damage can make eating them unappealing and reduce yield. Early plantings are most affected as adults emerge from overwintering with a voracious appetite. Eggplant is another frequent victim – damage can stunt small plants severely. Flea beetles are also common on potatoes and sweet corn. Robust well-established plants may not experience yield reduction.
Flea beetles are best managed with a combination of cultural practices and physical barriers. Establish fall brassicas away from spring plantings, and rotate crops regularly. Place row covers or insect netting over susceptible crops to exclude emerging flea beetles. Set out larger, rather than smaller transplants. Transplant eggplant into black plastic mulch or landscape fabric to speed up establishment. Ensure plants have adequate water and fertility during establishment. Consider fertilizing damaged plants to help them through. Protectants such as kaolin clay (Surround®) can also be used to deter flea beetles. Consult your local Cooperative Extension Center for chemical recommendations, as several effective options are available.