Discipline: Biological Sciences
Zion Michael - Florida International University
Co-Author(s): Sang-Bin Lee, University of Florida ; Thomas Chouvenc, University of Florida ; Nan-Yao Su, University of Florida
Facilitating efficient resource transfer requires building an optimized transportation network which balances cost minimization with benefit maximization. This process often involves finding and using the shortest route to save time and energy. For animals which forage for food located remotely, optimizing their transportation networks is critically related to survival. Subterranean termites forage wood resources by excavating underground foraging networks for search and transport use. Because termites have no prior knowledge of food location during the food searching phase, establishment of optimized tunnel networks at the beginning of foraging is difficult. Thus, optimization should logically follow initial food discovery. Despite this knowledge, it remains elusive as to how subterranean termites optimize a transportation network and how they find the shortest route for food transportation. We simulated different scenarios using Coptotermes formosanus by providing different shapes and distances of pre-formed tunnels (simple, intermediate, and complex arenas) to food, where food items were located at a fixed distance from the arena entrance. Camcorders were mounted on top of each arena and videos were recorded for 24 hours from the moment termites started moving from the nest to the distributing chamber.Number of branching tunnels were compared with the Kruskal-Wallis test (P < 0.05). The distance of the shortest tunnel from the entrance to food source was subjected to one-way analysis of variance (ANOVA) with time and complexities as fixed factors. Then a Tukey’s HSD post-hoc analysis was used to discern statistically different groups. Tunnel widths of the pre-formed and newly-excavated tunnels in each arena were compared with one-way ANOVA with time as a factor, followed by Tukey’s HSD as a post-hoc analysis. For each time point and when applicable, a t-test was used to compare tunnel widths between pre-formed and the tunnel width of newly-excavated short tunnel for each complexity. In the intermediate arena, we compared tunnel widths of pre-formed and newly excavated tunnels at 18 and 24 hours. In the complex arena, we compared the tunnels widths at 6, 12, 18, and 24 hours. Termites in the simple arena continuously used the pre-formed tunnel, showing negligible branching efforts. However, termites in the intermediate and complex arenas followed the pre-formed tunnel only for the initial few hours before excavating many branching tunnels. This branching activity ultimately resulted in termites establishing shorter commuting routes than the preformed tunnels while the shortest route was widened over time. Once food is located, subterranean termites can actively alter tunnel networks to minimize the cost in food transportation. Future research involves simulating this study in NetLogo as doing so enables scope expansion by increasing control of parameter modification and capacity for replication.
Funder Acknowledgement(s): This work was supported by the USDA National Institute of Food and Agriculture, Hatch project numbers FLA-FTL-005865 and FLA-FTL-005660, and Broadening the STEM Pipeline with Research Experiences in Agricultural Science funded by the USDA NIFA REEU Program (#GRANT12124888).
Faculty Advisor: Sang-Bin Lee, firstname.lastname@example.org
Role: I helped conceptualize and design the study. I carried out the experiments; I interpreted results. I submitted a manuscript as lead author, which is currently under revision in the journal of Behavioral Ecology.