Ultraviolet cues affect the foraging behaviour of jumping spiders

Jumping spiders have long been known to have large principal eyes with ultraviolet (UV) receptors, and many species of their arthropod prey have body parts that reflect strongly in the UV waveband. However, no attempt has been made to investigate the effects of UV cues from prey on the foraging behaviour of jumping spiders. We performed laboratory experiments to test the hypothesis that jumping spiders use UV cues for locating and discriminating prey. We used Portia labiata, a web-invading, spider-eating jumping spider, as the predator and Argiope versicolor, an orb-web-building spider that decorates its web with UV-reflecting silk stabilimenta, as prey. Portia labiata could detect the difference between UV-reflecting and non-UV-reflecting stabilimentum-decorated webs and they preferentially approached the UV-reflecting ones. These findings may have wide implications for studies of animal foraging, and support one hypothesized function of salticid UV vision, the role of which is largely unknown.