ACEPHATE AS A POTENTIAL MANAGEMENT TOOL OF HELICOVERPA-ZEA (LEPIDOPTERA, NOCTUIDAE) IN SNAP BEAN

Laboratory bioassays with the com earworm, Helicoverpa zea (Boddie), w ere used to determine persistence and movement of foliarly applied ace phate in snap beans. Acephate was applied to snap bean foliage at five different vegetative stages (V-1 to V-5) and three reproductive stage s (R-1 to R-3). At the recommended field rate of 1.2 kg (AI)/ha, aceph ate did not translocate to the blooms or pods in concentrations high e nough to provide acceptable com earworm suppression regardless of plan t growth stage at application. Increase in acephate rate to two times or four times the recommended field rate failed to increase H. zea mor tality. Leaf-disk bioassays indicated that acephate persistence in fol iage was long. Under greenhouse conditions H. zea mortality was 72.9% at 14 d. Field studies indicated that single acephate applications, re gardless of application timing, were not as effective as the standard compounds used for H. zea suppression. Persistence on foliage, however , may provide acceptable suppression of other insect pests of snap bea n.