AGGRESSIVE BEHAVIOUR OF HARVESTER TERMITES HODOTERMES MOSSAMBICUS (HAGEN) AND TRINERVITERMES TRINERVOIDES (SJOSTEDT)

1. Individual males, females and pairs of primary reproductives of H. mossambicus developed strong aggressive reactions to each other after being isolated for approximately 24 hours. The intensity of the reactions was a function of the isolation period. Temperature had no significant influence on the reaction while digging in the soil intensified the reaction. 2. Laboratory colonies of H. mossambicus were only slightly aggressive but field workers from different colonies were strongly aggressive. Use was made of the aggressive behaviour of field workers to determine the area of the foraging territory of a colony. The mean area of 12 colonies was found to be about 1 000 ft2. 3. When four laboratory colonies of H. mossambicus were allowed to coalesce, the resulting colony retained only one pair of reproductives and destroyed the others. 4. T. trinervoides colonies collected in the field fought to the death in the laboratory. Workers attacked workers in the absence of soldiers and vice versa. 5. H. mossambicus workers and soldiers were not attacked by T. trinervoides soldiers although the two species fought and many individuals were killed when they were forcibly mixed. © 1968 Masson & Cie.