How spiders actively modulate web-vibration sensing for prey localization*

Organisms flexibly adjust postures and movements to acquire information from environments based on real-time sensory feedback. Despite the ubiquity of vibrational sensation in animals, less is known about how behavioral dynamics modulate vibratory sensory information.

This study aims to understand how spiders actively perform a series of sensorimotor actions to modify the vibrational sensory field during prey capture. We hypothesize that orb-weaving spiders actively adjust leg postures and produce web vibrations to increase sensory gain. By quantifying the web vibrational landscape elicited by Drosophila, we manually perturb the web with well-defined frequencies and amplitudes to identify how leg posture is altered as a function of web perturbation. We found that spiders repeatedly crouch and stretch the silk during prey localization, suggesting an active vibration sensation. We will identify the mechanical properties and vibration sensitivity as a function of leg postures of the vibration sensor. By combining these measurements, we will be able to characterize the dynamics of leg posture and infer how the spider modulates leg vibration sensitivity to detect prey. Importantly, this study will improve our understanding of sensorimotor integration of substrate vibration sensation.