Dose-dependence in attraction to (E)-8-dodecenyl acetate by the giant eucosma moth, Eucosma giganteana, and its implications for management of silflower

Silphium integrifoluim is a novel perennial oilseed crop that is currently under development as a more sustainable alternative to sunflower. However, preventing its widespread commercialization, in part, is its specialized pest, Eucosma giganteana (Lepidoptera: Tortricidae). This moth decimates S. integrifolium’s seed production and there is not a consistent pest management strategy for dealing with this pest that is not wildly disruptive to production. A known attractant, (E)-8-dodecenyl acetate, has been used for multiple years to lure adult E. giganteana onto clear sticky traps. During the field season in 2023, two linear doses (5.75 and 7.75 μl/mg) of this attractant were tested and although the higher dose yielded a higher number of individuals numerically, the difference was not significant between the two doses. This could have been because the doses were too similar to each other. For the 2024 field season, we examined three doses of this attractant with exponential increases (5.75, 78.5, 580.4 μl/mg) from the lower dose used in 2023. Contrary to the prior year, we found exponentially higher doses resulted in a dose-dependent increase in attraction by E. giganteana. Next steps include applying the attractant on an area-wide basis to understand whether it can shut down trap capture of E. giganteana, as would be expected under mating disruption. Dose-dependency illustrates (E)-8-dodecenyl acetate has promise for a behaviorally-based strategy to protect silflower.