Chemical characterization of the alarm pheromone in the venom of Polybia occidentalis and of volatiles from the venom of P-sericea

The contents of the venom sacs of the two epiponine species Polybia occiden talis (Olivier) and P. sericea (Olivier) (Hymenoptera: Vespidae) have been analysed by GC-MS for their volatile constituents. The mixture of volatiles was found to be very diverse in both the species. The spiroacetal (E,E)-2, 8-dimethyl-1,7-dioxaspiro[5.5]undecane, was present in both species and was the major component in P. occidentalis, where it was determined to show (2 S,6R,8S)-configuration. An enantiomerically pure synthetic sample was teste d in field bioassays on P. occidentalis colonies and was clearly shown to e licit alarm behaviour.