Diamondback moth management with mating disruption

Diamondback moth [DBM, Plutella xylostella (L.) (Lepidoptera: Plutellidae)], is the most important lepidopteran pest of brassica crops globally. Insecticide resistance in DBM populations has led to a need for alternative IPM strategies. The ability to synthesize large quantities of the two key components of the natural DBM sex pheromone, (Z)-11-hexadecenal and (Z)-11-hexadecenal acetate has equipped researchers with the tools needed to not only monitor DBM male moths but to manage the pest using mating disruption. First initiated in the 1990s, mating disruption was promoted as an insecticide resistance management tool for DBM, but the approach was not widely adopted due to inconsistent results with early pheromone dispensing systems and sprays that required re-applications. However, recent advancements in pheromone dispenser technology (slow-release season-long capabilities), improved understanding of the mechanisms of mating disruption and the widespread occurrence of DBM populations resistant to insecticides, has rekindled interest in mating disruption as an alternative IPM tactic for DBM. From 2022 to 2024 on commercial farms in Virginia, North Carolina, and South Carolina, we evaluated a new mating disruption technique using PVC-based MESO™ dispensers from Trécé Inc. (Adair, OK) containing a high-dose concentration that provided season-long slow release of the DBM sex pheromone. Results have been extremely promising resulting in shut down of male moth activity in treated fields along with concomitant reductions in larval damage to crops. Additional tactics and dispenser technologies for DBM mating disruption are also being explored.