Identification and bioassay of macrocyclic lactone sex pheromone of the halictine bee Lasioglossum zephyrum

The macrocyclic lactones found in the Dufour's gland of the halictine bee Lasioglossum zephyrum are female sex pheromones. Octadecanolide, eicosanolide, docosanolide, and tetracosanolide, as well as monounsaturated homologs of each, are components of the Dufour's gland secretion of this species. Furthermore, a series of odd-carbon-numbered saturated and unsaturated hydrocarbons and isopentenyl docosanoate occur in extracts of the Dufour's gland and of whole females. Two different mixtures of all four synthetic lactones, and additionally a treatment consisting of the natural extract, elicit higher response levels than two of the lactones separately or either of the controls.