Attraction of brown marmorated stink bugs, Halyomorpha halys, to blooming sunflower semiochemicals

I tested whether the brown marmorated stink bug (BMSB), Halyomorpha halys, discriminates among phenological stages of sunflower, Helianthus annuus. When BMSB females in a still-air laboratory experiment were offered a choice of potted sunflowers at distinct phenological stages (vegetative, pre-bloom, bloom, seeding), most females settled onto blooming plants. In moving air olfactometer experiments, testing each plant stage versus one another, for the attraction of BMSB females, blooming sunflowers overall were most attractive. Analyzing the headspace odorants of each plant stage revealed a marked increase of odorant abundance as plants transitioned from pre-bloom to bloom. Thirteen blooming-stage odorants elicited responses from female BMSB antennae. A synthetic blend of antennally-active odorants attracted BMSB females in laboratory olfactometer experiments, and in field settings enhanced the attractiveness of BMSB pheromone as a trap lure, particularly in spring. Sunflower semiochemicals coupled with synthetic BMSB pheromone could be developed to improve efforts to monitor and control BMSB populations.