Bill Brink, Crop Systems Extension Educator, Springfield Extension Center, indicated that corn flea beetle injury was evident on 2- to 3-leaf stage corn plants. Densities of flea beetles averaged about two per plant. Dennis Epplin, Crop Systems Extension Educator, Mt. Vernon Extension Center, reported a severe flea beetle infestation in Wayne County on seedling corn plants (VE to V1 stage). As reported in an earlier issue of the Bulletin, inbreds that are susceptible to Stewart's wilt are most at risk for infestations of corn flea beetles. Fields planted to these inbreds should be carefully monitored this spring. Plan to check at least 20 plants in each of five areas of a field for flea beetles. Make sure that you examine the upper and lower portions of leaves. During bright, sunny days, flea beetles are likely to be "tucked" away on the lower surface of leaves. The Seed Corn Pest Management Manual for the Midwest, published by Purdue University, provides the following recommendation: |
Prior to the V5 stage of development, control may be necessary if 10 percent of the plants inspected show severe corn flea beetle feeding damage (plants begin to look silvery or whitish, or leaves begin to die) and approximately 2 to 3 or more flea beetles per plant are found.
This seed corn pest management manual provides a great deal of useful information on scouting tips and economic thresholds. To order a copy, contact the Purdue Pest Management Program, 1158 Entomology Hall, Purdue University, West Lafayette, IN 47907, or call John Obermeyer at (765)494-4563.--Mike Gray