European Corn Borer Control, 1997

Abstract

Abstract This planting was seeded on 25 Jun at the Fruit and Vegetable Research Farm near Geneva, NY, using a tractor-powered two-row seeder planting 8 seeds/ft. Plots consisted of two rows 50 ft long with 3 ft row widths. Each plot was separated by two untreated buffer rows to minimize spray drift. Each treatment was replicated four times in a RCB design with a 20-ft buffer zone between adjacent replications. In this trial, larvae were inoculated in each plot twice, about 24 h pre- and post-spray, respectively. It was necessary to infest snap bean plots with ECB with colonies because exceedingly low levels of natural infestation of beans by this pest in this climate precluded statistical comparisons among 1 treatments. Plants were in varying stages of development (i.e., pre-bloom to pin pod) at the time of larval inoculation, the majority being in late bloom. On 18 Aug, an estimated 595 ECB first instars were placed on 30 ft of each treatment row in each replication. Before the inoculations were initiated, larvae were evenly dispersed in corncob grits. They were then applied evenly over the plants with a Davis Insect Inoculator (Bio-serv, Inc., P.O. Box 450, Frenchtown, NJ 08825). The plant foliage was moistened with water before the inoculations using a backpack sprayer so that the mix of corn cob grits and larvae would adhere to the foliage. On 19 Aug, spray treatments were applied using a CO2 powered tractor mounted six nozzle boom delivering 45 gal water/acre at 40 lbs psi. The second inoculation consisted of about 560 ECB larvae placed on only 15 ft of each treatment row on 20 Aug. Thus, there were portions of each row that received two inoculations (simulating two oviposition periods) while the rest of each row (clearly marked and staked) received only the first inoculation (simulating a single oviposition peak). Plants were inspected for ECB injury and larvae on 8 Sep by pulling out all plants in the 30-ft inoculated sections, thus including plants that were inoculated both once and twice.