HIGH CLEARANCE SPRAYER METHODS FOR APPLICATION OF CORN-ROOTWORM (COLEOPTERA, CHRYSOMELIDAE) SEMIOCHEMICAL-BASED BAITS

Application of a semiochemical-based bail to silking corn (Zea mays L. ) with a high clearance sprayer effectively reduced the numbers of nor thern, Diabrotica barberi Smith & Lawrence, and western, D. virgifera virgifera LeConte, corn rootworm adults during studies conducted in 19 94 and 1995. Bait was applied using water volumes of 19 and 37 L/ha ab ove canopy nozzles vs nozzles on drop lines, and nozzles on drop lines on every row vs nozzles on drop lines on alternating rows. There were no significant differences among the high clearance sprayer nozzle co nfigurations in reducing corn rootworm beetle populations; however, no zzles on booms above the canopy were more likely to deliver discrete d roplets and were less likely to break due to entanglement of the drop lines with foliage. Semiochemical insecticide-baits had minimal effect s on predaceous adults of the family Coccinellidae. Seven coccinellid species were observed in the plots in 1994 and 4 species in 1995.