Species-specific blends of shared pheromone components minimize interspecific attraction among cerambycid beetles in the subfamily Lamiinae

Research over the last decade has revealed extensive pheromonal parsimony within the

large beetle family Cerambycidae, with many species producing the same, or very similar

aggregation-sex pheromones. Interspecific attraction may be minimized among species in the

subfamily Cerambycinae by temporal segregation, or by minor pheromone components that

strongly synergize attraction of conspecifics, or inhibit attraction of heterospecifics to the

dominant components. Less is known about pheromones of species in the largest subfamily, the

Lamiinae. Most lamiine species of eastern North America are restricted to flying during summer

and only at night, suggesting that they are less likely to be segregated temporally.

In this study, we identify the pheromone components of three lamiine species to test the

hypothesis that interspecific attraction is minimized by differences between species in

pheromone composition. Headspace collections from males of all three species contained 6,10-

dimethyl-5,9-undecadien-2-one (“geranylacetone”), but the species differed in stereochemistry of

the structurally related (E)-6,10-dimethyl-5,9-undecadien-2-ol (“fuscumol”) and/or (E)-6,10-

dimethyl-5,9-undecadien-2-yl acetate (“fuscumol acetate”). Male Astyleiopus variegatus

(Haldeman) produced S-fuscumol and S-fuscumol acetate, male Astylidius parvus (LeConte)

produced R- and S-fuscumol and R-fuscumol acetate, and male Lepturges angulatus (LeConte)

produced R- and S-fuscumol acetate. Field bioassays revealed that geranylacetone was a

powerful synergist for A. variegatus and L. angulatus, and that all three species were most

strongly attracted to blends of synthetic pheromones that simulated the composition of volatiles

produced by their males, supporting our hypothesis.