Multiple applications of pyrethroid insecticides are used to manage European corn borer, Ostrinia nubilalis Hübner, in snap bean, but new diamide insecticides may reduce application frequency. The objective of this study was to examine the potential for improving control of O. nubilalis in processing snap bean with diamide insecticides. Specifically, we compared O. nubilalis control with chlorantraniliprole, cyantraniliprole, and bifenthrin at three different phenological snap bean stages (i.e., bud, bloom, pod formation) to determine the duration of residual activity for each insecticide under field conditions in snap bean, and co-applied cyantraniliprole and bifenthrin insecticides with either herbicides or fungicides at each vegetative stage to determine if tank mixing cyantraniliprole and bifenthrin with common agrochemicals would reduce O. nubilalis control, and finally we confirmed the suitability of diamide insecticides for O. nubilalis control using commercial snap bean fields and processing plant contamination data, over two consecutive field seasons. Cyantraniliprole applications timed either during bloom or pod formation controlled O. nubilalis better than similar timings of bifenthrin. Co-applications of insecticides with fungicides controlled O. nubilalis as well as insecticide applications alone. Insecticides applied either alone or with herbicides during bud stage did not control this pest. In commercial snap bean fields, yield and quality were equivalent in fields treated once with chlorantraniliprole and twice with pyrethroids. Diamides are an excellent alternative to pyrethroids for manage O. nubilalis in snap bean. Adoption of diamides by snap bean growers could improve the efficiency of production by reducing the number of sprays required each season.
Soil Science Extension
University of Wisconsin Madison