Seasonal Activity, Spatial Distribution, and Physiological Limits of Subterranean Termites (Reticulitermes Species) in an East Texas Forest.

Abstract

Simple SummaryFor species with similar resource requirements to inhabit the same location, they must somehow divide or share resources. In subterranean termites, multiple species often co-occur where they consume decomposing wood. How these species partition wood resources within an environment is poorly understood. We characterized the foraging activity of three species of Reticulitermes subterranean termites in a single site for 28 months to investigate the means by which resources are partitioned. We tested if species utilize resources under different climatic conditions by comparing the termite activity in wooden monitors to measurements of soil temperature and moisture. Generally, Reticulitermes termites foraged more during warmer, dryer months but each species responded differently to soil temperature and moisture. We found that R. flavipes was able to forage for longer durations and continued foraging during periods of high soil moisture, R. hageni increased foraging under higher soil moisture, and R. virginicus increased foraging under lower soil temperature. These results suggest that resources may be partitioned through differential foraging activity in response to different environmental conditions.One of the major goals of ecology is to understand how co-habiting species partition limited resources. In the eastern U.S., at least three species of Reticulitermes subterranean termites often occur in sympatry; however, little is known about how these species divide food resources. In this study, we characterized the foraging activity of Reticulitermes flavipes (Kollar), R. hageni Banks, and R. virginicus (Banks) across seasons to assess the impact of environmental conditions on resource partitioning. A field site consisting of two grids of wooden monitors was sampled monthly for 28 months. Foraging activity in all three species was correlated with the interaction of temperature and moisture. This correlation was influenced by temperature and moisture approximately equally in R. flavipes, whereas temperature contributed more to the correlation in R. hageni, and moisture contributed more in R. virginicus. These differences caused each species to preferentially forage during specific environmental conditions: R. flavipes continued foraging after high moisture events, R. hageni increased foraging under higher soil moisture, and R. virginicus increased foraging under lower soil temperatures. We attempted to explain these patterns by the species’ physiological limits; however, we found no differences in upper lethal limit, desiccation, or submersion limits across species. These results add to the overall understanding of resource partitioning by emphasizing the ability of multiple species to utilize the same resource under different environmental conditions and raise questions regarding the physiological and/or behavioral mechanisms involved.