2-Undecyloxy-1-ethanol in combination with other semiochemicals attracts three Monochamus species (Coleoptera: Cerambycidae) in British Columbia, Canada

Two species in the genus Monochamus Dejean (Coleoptera: Cerambycidae: Lamiinae) have recently been shown to have the same male-produced sex pheromone, 2-undecyloxy-1-ethanol (monochamol), suggesting that other congeners may share the same pheromone. We tested that hypothesis by conducting field bioassays of monochamol, in combination with bark-beetle pheromones and the host plant volatiles ethanol and α-pinene, in southern British Columbia, Canada. We captured 603 Monochamus clamator (LeConte), 63 Monochamus obtusus Casey, 245 Monochamus scutellatus (Say) (tribe Monochamini), and 42 Acanthocinus princeps (Walker) (tribe Acanthocinini). All three Monochamus species were significantly attracted to the combination of monochamol and host plant volatiles, whereas bark-beetle pheromones plus plant volatiles and plant volatiles alone were minimally attractive. Adding bark-beetle pheromones to the monochamol plus plant volatiles treatment synergised attraction of M. clamator, but not the other two Monochamus species. Acanthocinus princeps was most strongly attracted to the combination of bark-beetle pheromones and plant volatiles, and did not appear to be affected by the presence or absence of monochamol in baits. We conclude that monochamol is a likely pheromone component for the three Monochamus species, and that monochamol plus host plant volatiles is an effective attractant for these and perhaps other North American Monochamus species.