Directional Orientation of Reticulitermes flavipes (Isoptera: Rhinotermitidae)

Subterranean termites moving in the peripheral tubular network of their foraging area need to distinguish the trail direction. In a natural gallery or tunnel network of Reticulitermes flavipes the branches at bifurcations generally have an acute angle between them. The resulting obtuse angle from the main trail leading into a branch is preferred by commuting termites. In experiments with artificial gallery forks, termites returning from a food source only neglected the trail junction leading to the nest and preferred the trail to a second food source if the angle to the nest was acute. A right angle to the nest was preferred over a straight way leading to a second food source. This preference to the nest increased when the three branches at trifurcations were arranged equi-angular. This preferred orientation could be attributed to attracting odours from close-by gallery material. Additionally, R. flavipes moved more slowly towards a food source consisting of pine wood than on the way back to the nest, as was shown in artificial one-way galleries. However, the significance of this speed difference remains uncertain because the speed of a homing termite in an artificially reversed trail does not slow down to the speed of a food foraging termite.