Evaluating a polyculture trap crop for organic management of Halyomorpha halys and native stink bugs in peppers

Organic farming systems are significantly challenged by the invasive Halyomorpha halys (Stål) and native stink bug species that injure vegetable crops. This two-year study evaluated a polyculture trap crop composed of sunflower and sorghum for organic pepper production at 11 sites in 8 mid-Atlantic and Southeastern states. Stink bug densities in the trap crop and peppers were recorded weekly (mid-June through September), and stink bug fruit injury was compared for trap crop-protected and unprotected control peppers. The trap crop was highly attractive, harboring 5–50× more stink bugs per m 2 than the peppers and providing an 8-week attraction period coinciding with peak stink bug activity. Despite this attractiveness, the trap crop was not effective at diverting adult stink bugs away from the pepper crop during the early fruiting period at most sites. However, the average density of stink bug nymphs in pepper plots surrounded by trap crops was 4× lower than controls 5 weeks after planting for pooled sites. Trap crop-protected peppers also had significantly less injury compared to control peppers pooled across sites and years. However, the resulting reduction in pepper damage was insufficient to be economically viable. Overall, results provide evidence that a polyculture trap crop was most effective during the latter weeks of the pepper crop cycle. Future research should address spatial arrangement of the trap crop or integration of complimentary management tactics within the trap crop earlier in the growing season to target the initial colonizing adult stink bugs.