Description

The corn flea beetle is a very small (1/16 in. long) black beetle found on the foliage of grasses and field corn (Photo 5-4). As the adult beetle is approached its common defensive behavior is to use its enlarged hind femurs to jump; hence the name flea beetle.

Distribution, damage and impact

Little is known about the corn flea beetle in Arkansas. Surveys have detected low numbers on field corn at Marianna and Des Arc, however, it likely occurs throughout the state. Adults damage field corn by feeding on the epidermis of the leaf. Damaged foliage has light colored streaks that may give the corn a silver appearance. In addition to foliar damage, the corn flea beetle is capable of transmitting Stewart’s wilt disease.

Life History

The corn flea beetle adult overwinters on grasses including weeds and grass crops like wheat in Arkansas. With warm temperatures in late winter, adults begin to feed, mate and lay eggs in the soil near grasses and corn seedlings. Larvae develop on roots and stems within the soil, pupate and adults emerge to begin the process again. Multiple generations occur each year. Flea beetle problems are greatest following mild winters.

Management

The threshold for corn flea beetle is not clearly defined but more than two adults per seedling (5-leaf or smaller), may warrant foliar insecticide application. In fields with soil applied insecticides at planting it is unlikely that high number of flea beetles will develop. Many of the current field corn hybrids possess some resistance to Stewart’s wilt.

Insecticide recommendations for corn flea beetle on field corn

See Table 5-2 for insecticide recommendations current at time of publishing. Current updated recommendations can be found in the Cooperative Extension Service publication MP-144 and on the world wide web at WWW.cdms.net/manuf/default.asp. Always follow instructions on pesticide labels.