SPECULATIVE HUNTING BY AN ARANEOPHAGIC SALTICID SPIDER

Portia fimbriata, an araneophagic jumping spider (Salticidae), makes undirected leaps (erratic leaping with no particular target being evident) in the presence of chemical cues from Jacksonoides queenslandicus, another salticid and a common prey of P.fimbriata. Whether undirected leaping by P.fimbriata functions as hunting by speculation is investigated experimentally. Our first hypothesis, that undirected leaps provoke movement by J. queenslandicus, was investigated using living P.fimbriata and three types of lures made from dead, dry arthropods (P.fimbriata, J. queenslandicus and Musca domestica). When a living P.fimbriata made undirected leaps or a spring-driven device made the lures suddenly move up and down, simulating undirected leaping, J. queenslandicus responded by waving its palps and starting to walk. There was no statistical evidence that the species from which the lure was made influenced J. queenslandicusʹ response in these tests. Our second hypothesis, that J. queenslandicus reaction to J. queenslandicus when J. queenslandicus reacted to lures simulating undirected leaping. In these tests, P.fimbriata responded by turning toward J. queenslandicus and waving its palps.