C-6-6
ORGANIZATION OF FOOD EXPLOITATION IN THE TERMITE CHEDORHINOTERMESLAMANIANUS: INTERACTION OF TWO PHEROMONE SYSTEMS.
Judith Reinhard1 and Manfred Kaib2
1 Bundesanstalt für Materialforschung und -prüfung,Lab. IV.11, D-12200 Berlin, Germany.
2 Universität Bayreuth, Lehrstuhl Tierphysiologie,D-95440 Bayreuth, Germany.
Chemical signals from secretions of different exocrine glands modulatea variety of behavioural patterns in termite societies. During food exploitation,workers of the African termite Schedorhinotermes lamanianus (Isoptera:Rhinotermitidae) employ on foraging trails the trail pheromone from thesternal gland, both for orientation and recruitment to a food source. Thesecretion from the labial gland, released onto the food by gnawing termites,carries a pheromone, which stimulates additional workers to gnaw at thesame site and thus leads to the formation of aggregations of gnawing termites.An interaction between these two pheromone systems during food exploitationis demonstrated for the first time: The volatile signal from the sternalgland inhibits in a dose-dependent manner the non-volatile, highly persistentsignal from the labial gland. The development of gnawing-aggregations isinhibited and established ones are dissolved. Behavioural evidence is giventhat both signals are perceived by antennal sensilla, the volatile signalfrom the sternal gland by olfactory neurones and the non-volatile signalfrom the labial gland by gustatory neurones. We discuss the interactionof the two pheromone systems as basis for the development of distinct transporting-and gnawing-zones, and as a means for a dynamic regulation of food exploitation.