Are trichobothria used in terrestrial prey capture by the yellow scorpion Tityus serrulatus Lutz & Mello, 1922 (Buthidae)?

Abstract

Many arachnids rely on substrate-borne vibrations and air displacement to detect prey. Air-flow stimuli may be detected by long setae called trichobothria, which occur on scorpion pedipalps, but seldom have their functions been addressed in these animals. We tested the hypothesis that trichobothria on scorpion pedipalps are important for capturing terrestrial prey in the scorpion Tityus serrulatus. We predicted that scorpions with trichobothria experimentally removed would be less successful in capturing terrestrial prey than the control groups. We also predicted that scorpions without trichobothria would have a higher number of capture attempts, that the latency to detect prey and to the first capture attempts would be higher, and the number of times that scorpions oriented their body towards the prey would be lower. We used an experimental subject and a cricket in an arena with a paper sheet as substrate. We did not find differences in the measured variables between the groups. Other sensory organs, such as basitarsal compound slit sensilla and tarsal hairs would enable scorpions to detect prey by substrate-borne vibrations, compensating for the lack of trichobothria. Our results suggest that the trichobothria of T. serrulatus may not be essential to capture terrestrial prey.