Choosing substrates with or without predator cues by <em>Prionostemma</em> Opiliones

We experimentally tested for the avoidance of predator cues in an arachnid that relies on contact chemoreception and frequently loses its legs, the Neotropical Opiliones in the genus Prionostemma. First, we tested whether these arachnids can detect and avoid chemical cues derived from potential predators. When choosing between leaf litter substrates with or without the urine of a sympatric predator (the toad Rhinella horribilis), individuals preferred the substrate lacking the predator cue. Second, we tested that substrate choice would be affected by previous leg loss, given a potential reduction in sensory detection with fewer sensory organs. However, we found that individuals with autotomized legs were just as likely to avoid substrates with predator chemical cues as intact individuals.