Using blends of cerambycid beetle pheromones and host plant volatiles to simultaneously attract a diversity of cerambycid species

We evaluated the attraction of native species of cerambycid beetles to blends of cerambycid pheromones and the host plant volatiles ethanol and α-pinene to determine whether such blends could be effective lures for detecting and monitoring multiple species. The complete six-component blend of pheromones included racemic 3-hydroxy-2-hexanone, 2,3-hexanediol isomers, (E)-6,10-dimethyl-5,9-undecadien-2-ol and the corresponding acetate, 2-(undecyloxy)-ethanol, and racemic 2-methyl-1-butanol. Bioassays in east-central Illinois captured 3070 cerambycid beetles of 10 species, including four species in the subfamily Cerambycinae (Neoclytus acuminatus (Fabricius, 1775), Neoclytus mucronatus (Fabricius, 1775), Phymatodes lengi Joutel, 1911, and Xylotrechus colonus (Fabricius, 1775)) and six species in the subfamily Laminiae (Aegomorphus modestus (Gyllenhal in Schoenherr, 1817), Astyleiopus variegatus (Haldeman, 1847), Astylidius parvus (LeConte, 1873), Graphisurus fasciatus (DeGeer, 1775), Lepturges angulatus (LeConte, 1852), and Monochamus carolinensis (Olivier, 1792)). Beetles were attracted to their pheromone components within the blend, with inhibition only evident in one species. Host plant volatiles synergized attraction for some species, and synergism usually was attributed to ethanol, with α-pinene enhancing attraction only for the pine specialist M. carolinensis. The optimal strategy for targeting a broad range of cerambycid species would be to bait traps with a blend of several pheromones plus ethanol and α-pinene because synergism by these plant volatiles is critical for some species, whereas strong inhibition is uncommon.