E-74
DEPARTMENT OF ENTOMOLOGY
vegetable insects

FLEA BEETLES
David L. Matthew, C. Richard Edwards, and Marlin K. Bergman,
Extension Entomologists

Flea beetles are small, hard-shelled insects, so named because their enlarged hind legs allow them to jump from plants like fleas when disturbed. They usually move by walking or flying, but when alarmed they can jump a considerable distance. Several different species are commonly found in vegetables, often damaging young plants so severely that they die.
Flea beetles can be identified by their characteristic type of damage. They feed by chewing a small hole (often smaller than 1/8 inch) in a leaf, moving a little, then chewing another hole and so on. The result is a number of "shot holes" in the leaf. While some of the holes may meet, very often they do not.
Flea beetle adults lay their eggs on the plant parts or in the soil around the base of a plant. The tiny larvae in the soil feed on the roots of the plant, often damaging edible crops. Flea beetles in general are not difficult to control, but often they will have already seriously injured crops before their numbers or extent of damage is realized. Also, flea beetles tend to become more numerous when susceptible crops are grown in the same area year after year. In Indiana, some species have multiple generations per year, while some have only one.

FLEA BEETLES FOUND IN INDIANA
Potato Flea Beetle. One of the most common and destructive, the potato flea beetle (black, 1/16 inch long) attacks potatoes, tomatoes, green pepper, eggplant and other solanaceous plants. Adults emerge from the soil in midspring and feed on the young foliage of these crops. They may also feed on sunflower,
morning glory, jimson weed and lambs-quarter. Larval feeding on potato tubers may cause roughness, pits and trails on the surface or in the tuber itself. These pits show up on peeled potatoes as black spots.
Spinach Flea Beetle. The largest of our common species, the spinach flea beetle adult is easily recognized. Almost 1/2 inch long, it has dark greenish black wing covers, a yellow-orange thorax and a dark head. Unlike the other species, the spinach flea beetle lays its eggs in clusters on leaf surfaces. Larvae feed on the undersides of leaves.
Some flea beetle species common to Indiana: (a) potato, (b) spinach, (c) palestriped and (d) striped.
COOPERATIVE EXTENSION SERVICE • PURDUE UNIVERSITY • WEST LAFAYETTE, INDIANA 47907