6-(4-Methylpent-3-en-1-yl)naphthalene-1,4-dione, a behaviorally active semivolatile in tibial perfumes of orchid bees
Male neotropical orchid bees (Euglossini) collect volatiles from varied sources in their environment to compile complex, species-specific tibial perfumes, which are later released at mating sites. A major compound prominent in tibial extracts of Euglossa allosticta was purified, as well as isolated and its structure was elucidated by analytical methods including GC–MS, GC–FTIR, HRMS and 1H and 13C NMR. After synthesis, the compound with the proposed structure was finally identified as 6-(4-methylpent-3-en-1-yl)naphthalene-1,4-dione. At field sites in Panama and Costa Rica, the synthetic compound attracted males of E. allosticta, but no other euglossines. This strengthens the view that semivolatiles play an important role in conveying specificity to perfume signals of orchid bees.
TE was funded by the German Science Foundation (EL 249/6 and 11) and EH, FA and NS were funded by the County Administrative Board of Västernorrland and by the European Union Regional Development Fund.