Seedcorn Maggot Control, 1988

Planting-time insecticides for seedcorn maggot control were tested at Ames, Iowa. The experimental design was a randomized complete block with 4 replicates. Treatments were applied to 40-ft-long rows on 30-inch spacing. The test was conducted in a field that had been planted to alfalfa. Approximately 1 wk prior to planting, manure was spread on the alfalfa and then plowed under to provide decaying organic matter that attracted ovipositing adult females. Granular insecticide formulations were applied with modified Noble metering units that had been calibrated to deliver material at 4 mph. The applicators were mounted on a 4-row John Deere Max-Emerge 7100 integral planter. Each row was monitored constantly to ensure that insecticide was being correctly applied at all times. Drag chains were used for incorporation. Examination of the seeds in the untreated check rows 10 d after planting revealed no damage, although pupae were found in the soil. At that time, adult emergence traps designed by Funderburk and Pedigo were placed over the rows. The galvanized steel trap, a rectangular bottomless box, has the following dimensions: length, 1,0 m; width, 0.2 m; height, 0.1 m. Fastened to the top of each trap were two 0.25-liter Mason jars with Tack Trap applied to the inside bottom. Two traps were placed over each treatment row. On Jun 3, the number of adults in the collection jars was counted and stand counts were taken. Data were subjected to ANOVA. No phytotoxicity was noted with any treatment. Dyfonate and Fortress were the only insecticides to significantly reduce adult emergence.