Description: With the exception of the larger spinach flea beetles, these pests are tiny, measuring just a few millimeters long. Most species are dark colored, and many have a metallic shine. Flea beetles are so named for their ability to jump when disturbed; they have large hind legs that give them a surprising vertical leap.
Life cycle: Adult flea beetles overwinter in leaf litter, garden debris, or other sheltered places. As temperatures begin rising in spring, the adults emerge and locate suitable host plants on which they feed. Some flea beetles will feed on weeds until garden crops are available. In late spring, female flea beetles lay eggs in the soil around the base of host plants. Tiny larvae feed on roots and root hairs for about a month, and then pupate in the soil. Multiple generations of flea beetles may occur in many areas.
Crops damaged: Corn, cucumbers, squash, melons, pumpkinds, gourds, eggplant, potatoes, tomatoes, cabbage, lettuce, celery, radishes, peppers, spinach, sweet potatoes, carrots, watermelon, and others depending on flea beetle species.
Signs and symptoms: Numerous small holes in plant foliage, giving leaves a buckshot-ridden appearance. Stunted or wilting seedlings. Blemished or pimples root crops.
- Keep the garden free of weeds, especially in early spring when emerging adult flea beetles are looking for food.
- Plant transplants instead of seeding directly, and the larger the better. Seedlings and small transplants are most susceptible to flea beetle damage.
- Use barriers – row covers or cheesecloth – on young plants to prevent flea beetles from feeding on them.
- Delay planting until later in the season, especially after mild winters. Early season flea beetles do the most damage, and will be more abundant if the winter weather wasn't cold enough to kill them.
- Use yellow sticky traps, available at home and garden centers, to monitor for flea beetles in the garden.
- Plant an early trap crop – radishes work well – to lure the flea beetles away from your more desired garden vegetables.
- At season's end, clear the garden of all debris and pull any weeds to minimize overwintering by adult flea beetles.