Burrowing Habits and Responses to Flood Events Among Riparian and Non-Riparian Wolf Spiders

Elaine Langone Center, Terrace Room

Spiders inhabiting dynamic boundaries between terrestrial and lotic systems are under constant risk of flooding and may have evolved adaptations to respond to rising water. Mechanisms for coping with periodic flooding have important implications for predicting species composition, recolonization, and resilience against flood-related disturbance for riparian arthropod communities. We examined burrowing propensities of riparian and non-riparian populations of three wolf spider species (Tigrosa helluo, Hogna lenta, and Trochosa ruricola) and also measured their emergence responses during simulated flood events. Spiders were housed in sleeved 35cm deep transparent containers with 25 cm of composite soil. The number of burrowing spiders, burrow dimensions, age and sex of each species were recorded. Spider containers were slowly flooded and emergence time from burrows were recorded. Both burrow depth and emergence latency from burrows of riparian H. lenta and T. helluo were half that of non-riparian populations. This pattern was not observed in T. ruricola. Both H. lenta and T. helluo burrow less than T. ruricola and their burrow positions and depth are different. Preliminary results suggest H. lenta and T. helluo have adaptively modified their behavior and burrow morphology to cope with inundation threats.