University of Illinois Extension

University of Illinois Extension

Hort Answers

Insect Damage

Flea Beetles
several genera

4 (1 = rare 5 = annual)
3 (1 = very little damage 5 = plants killed)
Eggplant, bean, radish, pepper, potato, tomato, spinach, and sweet corn.

Plants Affected

There are many species of flea beetles. Those most common on vegetables are black, 1/16- to 1/8-inch long adult beetles that may have light-colored stripes. They jump and fly when disturbed. The spinach flea beetle is almost 1/4 inch long, with a reddish neck. Although the larvae of most flea beetles live on roots, the spinach flea beetle larva lives on the leaves, is gray, and grows to be 1/4 inch long.

The adults eat tiny, pin-sized holes in leaves of eggplant, radish, bean, potato, tomato, and pepper. Pits may be eaten into the leaves; these pits later turn brown. Spinach flea beetle adults and larvae eat larger holes in spinach. Root-feeding larvae are rarely a problem. On sweet corn, corn flea beetle transmits Stewart's wilt.

Life Cycle

In general, flea beetles overwinter as adults under plant debris or other protective areas. Adults move to crop plants in the early spring and feed on leaves, causing cosmetic damage and sometimes reducing plant vigor and yield. Eggs are laid in the soil near base of the vegetable plants. Most vegetable flea beetle larvae feed on small roots. This root feeding causes very little damage. Development from egg to adult takes about a month. Summer adults also feed on foliage and damage leaves. For most species, there are two generations per year.

On cole crops, seedlings and transplants are the most critical stages for flea beetle control. Plant sweet corn varieties that are resistant to Stewart's wilt. For greens, treatment may be needed to avoid noticeable damage.

Related Resources
Home, Yard & Garden Pest Guide
U of IL - Distance Diagnosis through Digital Imaging
U of IL - Plant Clinic