Morphology of the gallery system around the nest and gallery development under experimental conditions in the termiteMacrotermes bellicosus (Smeathman)

Summary In the Ivory Coast (Côte d'Ivoire) we analysed the structures and the lay-out of the underground gallery system of the fungus-growing termiteMacrotermes bellicosus. We found a radial pattern of principal and lateral galleries, as well as caves, depressions and vertical passages reaching a depth of 1–2 m. According to the results of our investigations the gallery networks built byM. bellicosus are unique among all known termite species;M. bellicosus constructs the densest (3.1 m/m²) and most superficial (2–6 cm under the surface) gallery networks among all comparable termite species investigated.Under experimental conditions involving an observation arena with a glass bottom, we were able to observe the dynamics of the radial development of the exploratory passages. We also observed the manner and rapidity of the termites' exploration of new ground, as well as the role played by the discovery of food in the design of the gallery system.We were able to show that, when food was scarce, the termites gained access to the arena much more rapidly, built a much denser gallery system and came up to the surface more frequently.