Factors that Influence Tunneling in the Eastern Subterranean Termite, Reticulitermes flavipes (Kollar) (Isoptera: Rhinotermitidae)1

Although subterranean termite (Isoptera: Rhinotermitidae) foraging behavior involves the construction of gallery systems in soil, few studies have examined how colony size or soil environmental factors influence rates of construction and morphology of gallery systems. In this study, we investigated the effects of soil texture, soil moisture, and termite density on the rate of tunnel construction and tunnel morphology in Reticulitermes flavipes (Kollar). Tunneling rate and tunnel morphology were measured in laboratory arenas by simulating a thin slice of subterranean habitat. Tunneling rates were faster in arenas containing soils with higher sand concentrations. High termite densities had little effect on tunneling rates in small gallery systems, but differences were observed after gallery systems became large. The rate of tunnel construction along edges of tunneling arenas was significantly greater than in the interior. Tunneling distance on days after the addition of water was higher than on days prior to adding water. Differences in tunnel morphology were variable and were not associated with treatment levels in any of these experiments. The results of this study suggest that R. flavipes tunneling rates are strongly influenced by environment, whereas tunnel morphology is variable but not associated with any of the factors we examined. Key environmental variables include soil texture, moisture availability, and tactile orienting stimuli.