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

Abstract

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.

A new synonym and seventeen new distributional records in South American Cerambycidae (Coleoptera), with notes on Chlorethe scabrosa Zajciw, 1963

“…Semiochemicals (pher-ISSN On-Line: 1807-0205 ISSN Printed: 0031-1049 ISNI: 0000-0004-0384-1825 omone and plant volatiles) and UV light were used as attractants. Except for Psapharochrus maculatissimus (Bates, 1861) (i.e., Silva et al, 2019), it is noteworthy to point that cerambycid species reported here were caught at random by the treatment traps and at insufficient numbers for statistics (data not shown).…”

“…In that occasion, conspecific adults of both sexes were caught with traps baited with general attractant pheromones for cerambycid beetles. Living adult beetles were used to obtain the attractant pheromone of the species and the results will be published elsewhere (i.e., Silva et al, 2019). Geographical distribution: This species was described from Jamaica.…”

Variations on a Theme: Two Structural Motifs Create Species-Specific Pheromone Channels for Multiple Species of South American Cerambycid Beetles

“…Thus, it will likely be necessary to estimate which enantiomer of each compound is produced by each species through bioassays of the enantiomers, or possibly non-racemic mixtures of the two enantiomers of each component. Such tests may prove very revealing, given several recent examples demonstrating enantiomeric discrimination, and synergism between enantiomers, for several cerambycid species [14,27,28].…”

“…For E. flexuosa and E. lenkoi, as soon as we found that the adults of both species were attracted by some treatment lures in the bioassays for E. assimilis (see Results), we deployed an extra set of four traps with the same attractants, to collect live adults of these species. We used cross-vane intercept panel traps (black corrugated plastic) hung from inverted L-shaped frames made from PVC pipe (for details see [14]). Rainwater was drained from the collection jars suspended below the traps by drilling 2-mm holes in the bottoms of the jars.…”

“…In particular, wood-boring cerambycid beetles are of major importance as potential invaders, because of the ease with which they are transported between continents in wooden products and packing materials by global commerce [9,10,12]. This parsimony also implies that the identification of pheromone components for one cerambycid species may subsequently expedite the identification of pheromones or likely pheromones for related target species [8,13,14].…”