Special organisation during exploration and foraging in the harvester termite, Trinervitermes geminatus

Abstract

When foraging parties of Trinervitermes geminatus leave their nests and subterranean galleries in search of food they lay pheromone trails. These trails have to be re-established at the beginning of every foraging excursion. Our paper describes the development of such foraging columns and the distribution of the termites on established trail networks. At existing forks in the trail traffic is often unequally distributed between the branches of the trail. If a termite arrives at a fork alone it tends to follow the more frequented of the two branches, but when walking in group formation termites often deviate to the other branch. When traffic is dense group formation is more frequent and at such times lone termites are more prone to deviation and once on the less frequented branch maintain their direction more persistently than when traffic is less dense. This explains the fact that minor trails are maintained during peak foraging activity and may be abandoned when activity decreases. The distribution of termites on a network is thus partially influenced by the level of general activity (social influence of the moment) and partially by the innate properties of the already established pheromone trail (influence of past social conditions).

The self-organizing exploratory pattern of the argentine ant

“…A wide corridor of the chemically unmarked area is thus systematically "swept" and marked in a minimum time with maximum economy, just as a broom with a wide brush (the front) and a narrow handle (the trail) sweeps a corridor. A highly similar exploratory pattern may be seen in the termites Nasutitermes lujae (Pasteels, 1965) and Trinervitermes geminatus (Rickli and Leuthold, 1986) as well as in the ants I. pruinosus and Solenopsis sp. (H611dobler, personal communication).…”

Systematic search for food in the subterranean termite Reticulitermes santonensis De Feytaud (Isoptera, Rhinotermitidae)

“…These are termite species typically with low soldier proportions (1-5%), in which soldiers are exclusively involved in alarm and defense behaviour protecting tunnel and gallery openings against intruders (Kaib, 1987;Wells and Henderson, 1993). Regardless of their feeding patterns, soldier-initiated foraging on the other hand is evident in some species within the Nasutitermitinae, Termitinae, and Rhinotermitinae (Hewitt et al, 1969;Jander and Daumer, 1974;Nutting et al, 1974;Oloo and Leuthold, 1979;Traniello, 1981;Omo Malaka and Leuthold, 1986;Rickli and Leuthold, 1987;Schedel and Kaib, 1987;Miura and Matsumoto, 1995). It is usually found in species with a rather high soldier proportion (up to 40%) like e.g., in the Nasutitermitinae or in Schedorhinotermes lamanianus, a species of the same family as R. santonensis (Deligne et al, 1981;Kaib, 1985).…”

Self-organized shortcuts in the Argentine ant

“…[7], L pruinosus [8], Eciton spp. [9], Trinervitermes geminatus [10], Pogonomyrmex badius [11], Leptogenys spp. [12]).…”