Foraging organization of the open-air processional lichenfeeding termite Hospitalitermes (Isoptera, Termitidae) in Borneo

Summary:

The temporal dynamics and social interaction in the foraging activities of the open-air processional termite Hospitalitermes (Termitidae, Nasutitermitinae) were studied in Borneo, Southeast Asia. H. medioflavus and H. sp. A tended to forage from evening to the next morning. On average foraging activity occurred every 3.2 days. Some synchronization of foraging events among colonies was observed, which appeared to be caused by rainfall levels.¶ Temporal dynamics during foraging activity was observed in detail using a photographic method for two species; H. medioflavus and H. rufus. Roughly 300,000 to 500,000 individuals participated in a single foraging event in both species. The soldier ratio was highest at the beginning and the end of the activity. Temporal patterns of behavior were different between soldier, major worker, medium worker and minor worker during foraging. The patterns of behavior are consistent with their tasks in the foraging activity. Soldiers lead the foraging column and protect it, major workers act as food carriers in the earlier stage while medium workers become the dominant food ball carriers in the later stage, and minor workers play the role of gnawers. Therefore, caste composition changes during foraging activity. Similar behavioral tendencies were recognized in both species. Measurement of workers' body weights revealed that workers not only carry balls of food from foraging sites but also feed directly at the foraging sites.