Nearly all kinds of plants are attacked by flea beetles. The vegetables most commonly damaged in Oklahoma are radishes, corn, eggplant, and potatoes.
Most flea beetles are small, oval insects (1/6 to 1/5 inch in length), and are bluish black, brown, or yellowish brown in color, and some are marked with red or yellow. The hind legs are distinctly enlarged and thickened, and these beetles jump readily when disturbed. Generally, flea beetles overwinter as adults in trash, leaves, grass, or rubbish.
The adults chew small, round holes in the leaves of plants, which is most serious early in the growing season, which injury can eventually kill infested leaves. In addition, some species can transmit plant diseases. On potatoes, larvae tunnel superficially on the surface of tuber leaving scars and increasing susceptibility to disease organisms.
Cultural methods are the best defense against flea beetle infestations. Keep fields free of weeds and destroy plant residues. Late planting favors growth of the host plant over establishment of flea beetles. Lastly, covering beds of seedlings with a gauze-like material prevents beetle entry. Plants can be treated with available insecticides, and should be treated when adults and damage (small, round holes in the leaves) appear.