The adult flea beetle is a tiny (1/10 inch long) black, brown or bronze beetle that can jump like a flea when you disturb it. You’ll know it’s around when you see the small, round “pinholes” they chew through leaves. They will attack most vegetables, flowers and weeds but are particularly fond of brassicas (cabbage family), potatoes, spinach, radishes and eggplant.
Flea Beetle Life Cycle
Flea beetles are found throughout North America. The larvae live in the soil and are thin, white, legless grubs with brown heads that feed on plant roots. Adult Flea Beetles emerge from the soil in spring to feed and lay eggs on the roots of plants. The adults die out by early July. Their eggs hatch in about a week. The larvae feed for 2 to 3 weeks then pupate in the soil. The next generation of adults emerges in 2 to 3 weeks. These voracious pests produce two to four generations per year before the final generation of adults settles down for overwintering.
These beetles are most damaging in early spring when an infestation can kill seedlings. As plants mature they are better able to survive and outgrow the damage, unless the beetles carried a plant virus.
Battling the Enemy
Prevention is often the best defense. The larvae overwinter in soil and can be destroyed with regular hoeing and cultivating. Be sure to remove all debris from previous crops and keep the area weed free. Weeds are an important early season food for flea beetle larvae. Without cover and food, the larva will starve.
