Publication E-74
July 1978
Purdue University
Cooperative Extension Service
West Lafayette, Indiana 47907
Flea Beetles on Vegetables
Alan C. York, Extension Entomologist
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 do most of their movement by walking or flying, but when alarmed they jump a considerable distance. Several different species are commonly found in vegetables, damaging young plants -- often so severely they die. With all flea beetles, a characteristic type of damage identifies them as the culprit. As they feed, they chew a small hole (often smaller than 1/8 inch) in a leaf, move around a little, chew another hole, and so on. The result is a number of small
holes resembling 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 seriously injure crops before you realize the extent of their damage or their numbers. Some of the flea beetles in Indiana have multiple generations per year, and some have only one.
POTATO FLEA BEETLE
One of the most common and destructive flea beetles, potato flea beetles attack potatoes, tomatoes, green pepper, eggplant, and other solanaceous plants. Adults emerge from the soil in midspring and feed on young foliage. 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 on peeled potatoes as black spots. Adults are controlled with foliar dusts or sprays, or with systemic insecticides applied at planting time. Soil treatments with non-systemic insecticides may help control larvae but are not generally recommended. Flea beetles tend to become more numerous when susceptible crops are grown in the same area year after year.
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 many of the other flea beetles, the spinach flea beetle lays its eggs in clusters on leaf surfaces. Larvae feed on the undersides of leaves. In addition to spinach, adults will feed on beets, chickweed, lambsquarter and
many other weeds.