Pheromone trapping began for western bean cutworm moths this past week. Though not initially impressive, see “Western Bean Cutworm Pheromone Trap Report,” this is just the beginning of an extended moth emergence and flight, with their peak activity expected 2-3 weeks from now. Those in high-risk areas, i.e., sandy soils, high moth flight and western bean cutworm history, should be gearing up for field scouting of corn, even those with Bt-traits.
Remember that WBC larvae are no longer susceptible to most of the Bt traits in our corn hybrids (including those in SmartStax hybrids) and therefore scouting, followed by timely insecticide sprays are really the only reliable control option for the vast majority of producers that are in the zone where this insect is common, principally the northern tier of counties in Indiana, extending into Michigan and parts of Ohio. Only Bt hybrids expressing the Vip3a toxin will offer reliable control of this pest, so be sure to know what you have in your field and scout as needed. See this handy Bt Trait Table to check where your hybrids fit in terms of the pests managed.