Canadian Forest Service Publications
A biologically active analog of the sex pheromone of the emerald ash borer, Agrilus planipennis. 2015. Silk, P.J.; Ryall, K.; Mayo, P.; MaGee, D.I.; Leclair, G.; Fidgen, J.; Lavallée, R. Journal of Chemical Ecology 41: 294-302.
Issued by: Atlantic Forestry Centre
Catalog ID: 36308
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The emerald ash borer, Agrilus planipennis (Coleoptera: Buprestidae) (EAB), is an invasive species causing unprecedented levels of mortality to ash trees in its introduced range. The female-produced sex pheromone of EAB has been shown to contain the macrocyclic lactone (3Z)-dodecen-12-olide. This compound and its geometrical isomer, (3E)-dodecen-12-olide, have been demonstrated previously to be EAG active and, in combination with a host-derived green leaf volatile, (3Z)-hexenol, to be attractive to male EAB in green prism traps deployed in the ash tree canopy. In the current study, we show that the saturated analog, dodecan-12-olide, is similarly active, eliciting an antennal response and significant attraction of EAB in both olfactometer and trapping bioassays in green traps with (3Z)-hexenol. Conformational modeling of the three lactones reveals that their energies and shapes are vary similar, suggesting they might share a common receptor in EAB antennae. These findings provide new insight into the pheromone ecology of this species, highlighting the apparent plasticity in response of adults to the pheromone and its analog. Both of the unsaturated isomers are costly to synthesize, involving multistep, low-yielding processes. The saturated analog can be made cheaply, in high yield, and on large scale via Mitsunobu esterification of a saturated ω-hydroxy acid or more simply by Baeyer-Villiger oxidation of commercially available cyclododecanone. The analog can thus provide an inexpensive option as a lure for detection surveys as well as for possible mitigation purposes such as mating disruption.
Plain Language Summary
The emerald ash borer, is an invasive insect causing unprecedented levels of mortality to ash trees in its introduced range. The natural sex pheromone of EAB is the female-produced macrocyclic lactone. This compound and its geometrical isomer, have previously been demonstrated to effectively trap EAB (mostly males) in green prism traps deployed in the ash tree canopy. In the current study, we show that a saturated analog is similarly active, These findings provide new insights into the pheromone ecology of this species. Both of the unsaturated isomers are costly to synthesize, involving multi-step, low-yielding processes. The saturated analog, however, is made cheaply, in high yield and large amounts from cheap readily available starting materials. The analog can thus provide an inexpensive option as a lure for detection surveys as well as for possible control purposes.