Semiochemical blockers of bark beetle attraction—the devil is in the details

Aggressive bark beetle species colonize healthy, vigorous trees by means of mass attacks that are organized and synchronized by aggregation pheromones. Semiochemicals capable of reducing bark beetle responses to aggregation pheromones have been identified for nearly every significant bark beetle pest, but surprisingly limited success has been achieved in using these compounds for pest management. We discuss some of the likely obstacles to success, in particular, problems with field deployment of releasers and an insufficient understanding of how the compounds function in the ecology of aggressive bark beetles.