Emerald ash borer, Agrilus planipennis (Coleoptera: Buprestidae), detection and monitoring in Canada

Abstract

Emerald ash borer (EAB), Agrilus planipennis Fairmaire, is an invasive pest causing extreme levels of mortality in ash (Fraxinus spp., Oleaceae) in the USA and Canada. Knowledge of buprestid chemical ecology is sparse, but the appearance of EAB in North America and its devastating ecological and economic impacts have afforded an opportunity to study its semiochemistry and biology in detail. We review the chemical ecology of EAB and the application of its sex pheromone, the female-produced (3Z)-dodecen-12-olide ((3Z)-lactone), and the green leaf volatile, (3Z)-hexenol, in operational surveys and experimental control strategies. Adding (3Z)-lactone to green sticky prism traps with (3Z)-hexenol on the south aspect of the tree canopy consistently increases trap captures and detection rates at low insect densities. This bait combination is more attractive than (3Z)-hexenol alone, especially when traps are in a competitive deployment. Using a 'push-pull' strategy, some nonhost volatiles deployed in ash trees significantly lower trap capture and may be useful in the push component, with a girdled tree treated with systemic insecticide constituting the pull component. We review reliable branch sampling techniques to estimate incidence and density of EAB which positively correlate with trap capture. We recommend using these combined tools to detect, delimit, and monitor EAB.