Evidence for UV-based sensory exploitation in Australian but not European crab spiders

Abstract

Some crab spiders reflect UV-light, thereby creating a deceptive signal that attracts prey to the flowers that they sit on. We conducted a survey of several Australian and European species of crab spiders and found that UV-reflection is common in Australian species but absent from European species. Furthermore, honeybees are attracted to UV-reflecting Australian spiders while they are either indifferent to or repelled by European crab spiders. We do not know if UV-reflection evolved once or several times independently in crab spiders endemic to Australia or whether UV-reflective spiders arrived in Australia more recently.