Foraging behavior of subterranean termites (Isoptera: Rhinotermitidae): Food discovery and movement of termites within established galleries

Abstract:
Unlike insects foraging above ground where individuals can explore over an area and then lay a recruitment trail for others to follow, subterranean termites search for food by constructing underground tunnels. Studies have showed that termite tunnel orientations are affected by physical irregularities and moisture and olfactory gradients in soil. In the featureless soil, termite tunnels are excavating in a nonrandom pattern that evenly partitions the search area to increase the search efficiency. The overall morphology of termite tunnels showed the characteristic fractal structure, and such structure is constructed one bite of soil at a time by individual termites. Our study showed that path integration is one mechanism by which termites orient their tunnels, and that external cues are not necessary for subterranean navigation. They appear to use self-reference for orientation. While the food searching and discovery by propagation of subterranean tunnels are nonrandom, the movement of termites among “discovered” food sources within the galleries is best described by a random model according to computer simulations.