ONTOGENY OF CEPHALIC VOLATILE PATTERNS IN QUEENS AND MATING BIOLOGY OF THE NEOTROPICAL STINGLESS BEE, SCAPTOTRIGONA-POSTICA

Chemical communication is an ancient yet still immensely important par t of reproduction. Amongst all invertebrates, the most sophisticated ' 'chemical languages'' are used by social insects. Here the sex- and ca ste-specific pheromonal messages consist of multicomponent mixtures. I n the neotropical stingless bee Scaptotrigona postica, an inhabitant o f dense tropical rain forests, the cephalic volatiles of a queen trans mit information on her reproductive status to males. A distinct ontoge netic pattern of the queen pheromone composition allows drones to disc riminate receptive virgins which are then chased during the short nupt ial flight through the forest understorey. By means of gas chromatogra phic/mass spectroscopic analyses, the numerous volatile compounds foun d in pentane extracts of individual bee heads could be identified. Qua litative as well as quantitative changes of these volatiles in the cou rse of imaginal development could be determined, and bioassays with sy nthetic compounds were undertaken in order to decode the chemical sign als used during the short encounter of a young queen and her mate.