Flea Beetles subfamily Alticinae
EN007
Flea Beetles subfamily Alticinae
Kimberly Stoner
Department of Entomology
Connecticut Agricultural Experiment Station
123 Huntington Street
P.O. Box 1106
New Haven, CT 06504-1106
Telephone: (203) 974-8480 Fax: (203) 974-8502
E-mail: Kimberly.Stoner@ct.gov
Where and When to Look
There are many different species of flea beetle, each of them specializing on one or a few related species of host plant. Young eggplant, potato and tomato plants are damaged by one group of flea beetles, two other species specialize on the cabbage family, other species feed on spinach, and and still others on corn. Typically, the flea beetles overwinter in weeds or leaf litter as adults, and begin feeding on their preferred host as early as possible in the spring. They lay eggs at the base of the host plant, and the larvae feed on roots during the summer. The adults reappear in late summer or fall, when a new generation has been produced.
Description
Adults: The flea beetle adults vary from 1/12 to 1/5 of an inch in size. They are typically black, sometimes with white stripes or other markings. They have antennae 1/2 to 1/3 the length of the body, and very thick powerful hind legs. They are difficult to catch because they are easily disturbed and jump long distances.
Larvae: The larvae are not easily seen due to their small size and their location in the soil, feeding on plant roots.
Damage: Because of their small size and active habits, flea beetles eat very little in each spot, and thus produce small, round holes in the leaf that look like tiny shot holes. This sort of damage often does not harm the plant or its yield unless the plant is small or the flea beetles are very numerous. Thus it is most important to protect the plant when it is first planted and there are still large numbers of overwintered flea beetles present. Flea beetles are a serious problem, however, for leafy vegetables because the feeding holes are unacceptable to many buyers and consumers.
Control Methods
Natural: The thorough removal of crop residues in the fall helps to minimize overwintering of flea beetles. Covering young plants with row cover or other fine-mesh material can protect the plants from flea beetles until they are well established. Starting seed in a protected environment can allow the plants to get large enough to tolerate flea beetles before they are transplanted to the field. Late planting can avoid the early spring peak in flea beetle numbers. Interplanting crops from different plant families, such as tomatoes and broccoli, can also reduce the numbers of flea beetles.
Chemical: Sevin, methoxychlor, rotenone, and pyrethrum are available in formulations labeled for control of flea beetles on various crops. Follow instructions on the label. Remember that large, vigorous plants of most crops can tolerate some flea beetle damage to leaves without losing yield.
Summary
Flea beetles are small, rapidly moving insects that eat tiny, round "shot-holes" in leaves of many vegetable plants. There are many species of flea beetles, each specializing on one or a few related species of host plant. They typically overwinter as adults and begin feeding early in the spring. They lay eggs at the base of the plant, where their larvae feed on roots, and adults feed again on the leaves in the fall. For most vegetables, cultural methods that protect small seedlings from the beetles are sufficient. Leafy vegetables, where cosmetic damage to leaves is important, may need protection throughout the season.