Enantiomers of fuscumol acetate comprise the aggregation-sex pheromone of the South American cerambycid beetle Psapharochrus maculatissimus, and likely pheromones of the cerambycids Eupromerella plaumanni and Hylettus seniculus

There is increasing evidence that pheromone chemistry within the large coleopteran family Cerambycidae is often highly conserved, with numerous related species sharing the same pheromone components. As a result, traps containing these components can attract multiple cerambycid species simultaneously. In the present study, we exploited this concept in the identification of the male-produced aggregation-sex pheromone of the South American species Psapharochrus maculatissimus (Bates) (Coleoptera: Cerambycidae, subfamily Lamiinae, tribe Acanthoderini). Initially, live adults of both sexes were caught using a trap baited with a lure containing a blend of known cerambycid pheromone components. Headspace volatiles were collected from live beetles and analyzed by coupled gas chromatography-mass spectrometry. Males of P. maculatissimus sex-specifically produced a 1:38 blend of (R)-fuscumol acetate ([2R,5E]-6,10-dimethylundeca-5,9-dien-2-yl acetate) and (S)-fuscumol acetate, which were both components of the pheromone lures to which they had been attracted. In more focused field trials, traps baited with the (S)-enantiomer, or a blend approximating the natural 1:38 ratio of (R)- to (S)-enantiomers, attracted adults of both sexes in approximately equal numbers. During bioassays, adults of the lamiine species Eupromerella plaumanni (Fuchs) (tribe Acanthoderini) and Hylettus seniculus (Germar) (Acanthocinini) also were attracted, but to different lures, with E. plaumanni being attracted to the racemic mixture of the two enantiomers of fuscumol acetate, whereas H. seniculus was attracted specifically to (R)-fuscumol acetate. Our results suggest that differences between these sympatric species in the stereochemistry of fuscumol acetate impart species-specificity to pheromone communication channels, similar to what has been found recently with lamiine species from other continents.