The effect of prior predator sensory experience on antipredator behavior and survival in the wolf spider Rabidosa rabida (Araneae: Lycosidae)
Adults of the wolf spider Pardosa milvina are predators of spiderlings of the larger co-occurring wolf spider Rabidosa rabida. Previous studies demonstrated that wolf spiders show effective antipredator behavior (reduced movement) in the presence of chemical cues (silk and excreta) from other species of wolf spider. We investigated the ability of naïve Rabidosa spiderlings to exhibit antipredator behavior with and without prior exposure to chemical cues or visual and vibratory cues of Pardosa. Naïve spiderlings were placed in containers alongside live Pardosa with and without Pardosa chemical cues. Spiderlings survived significantly longer in the presence of Pardosa silk and excreta compared to containers lacking these cues. We tested the effect of prior predator experience on spiderling behavior and survival in the presence of predator chemical cues. Spiderlings were exposed to one of five predator sensory treatments (N = 20/treatment): 1) predator visual and vibratory cues, 2) predator chemical cues only, 3) visual, vibratory, and chemical predator cues, 4) chemical cues from a cricket (Acheta domesticus), and 5) no previous exposure (control). Each trial consisted of a pre-exposure movement test, 24-h exposure to one of the five sensory treatments, a post-exposure movement test and finally a predation experiment with live Pardosa and associated chemical cues to assay the effectiveness of the spiderling's response. Results show a significant change in Rabidosa activity before and after exposure for all sensory treatments except the cricket and blank control. Treatments involving 24-h exposure to Pardosa chemical cues resulted in increased survival time in the predation portion of the experiment relative to other sensory treatments. We conclude that 1) Rabidosa innately responds to Pardosa silk and excreta, 2) extended exposure to predator chemical cues enhances Rabidosa antipredator response and survival, and 3) predator recognition is influenced primarily through chemical rather than visual or vibratory means.
