Heiling Astrid M, Cheng Ken, Chittka Lars, Goeth Ann, Herberstein Marie E
Department of Biological Sciences, Macquarie University, North Ryde, 2109 NSW Australia.
J Exp Biol. 2005 Oct;208(Pt 20):3925-31. doi: 10.1242/jeb.01861.
Australian crab spiders Thomisus spectabilis sit on the petals of flowers and ambush prey such as honeybees. White-coloured T. spectabilis reflect in the UV (UV+ spiders) and previous research has shown that their presence, curiously, attracts honeybees to daisies. We applied an UV-absorber (Parsol) to create UV-absorbing (UV-) spiders that did not reflect any light below 395 nm wavelength. These physical changes of visual signals generated by crab spiders caused honeybees to avoid flowers with UV- spiders on their petals. They also affected the perception of UV- spiders by honeybees and a potential avian predator (blue tits). Compared to UV+ spiders, UV- spiders produced less excitation of the UV-photoreceptors in honeybees and blue tits, which translated into a reduced UV-receptor contrast and a reduced overall colour contrast between UV- spiders and daisy petals. Our results reveal that a clean physical elimination of reflection in the UV range affects perception in predators and prey and ultimately changes the behaviour of prey.
澳大利亚蟹蛛（Thomisus spectabilis）栖息在花瓣上，伏击诸如蜜蜂之类的猎物。白色的澳洲蟹蛛能反射紫外线（紫外线反射型蜘蛛），先前的研究表明，奇怪的是，它们的存在会吸引蜜蜂飞向雏菊。我们使用了一种紫外线吸收剂（帕索1789）来制造不反射波长低于395纳米任何光线的紫外线吸收型（紫外线吸收型）蜘蛛。蟹蛛视觉信号的这些物理变化致使蜜蜂避开花瓣上有紫外线吸收型蜘蛛的花朵。这些变化还影响了蜜蜂以及潜在的鸟类捕食者（蓝山雀）对紫外线吸收型蜘蛛的感知。与紫外线反射型蜘蛛相比，紫外线吸收型蜘蛛对蜜蜂和蓝山雀的紫外光感受器产生的刺激较少，这转化为紫外线感受器对比度降低，以及紫外线吸收型蜘蛛与雏菊花瓣之间的整体颜色对比度降低。我们的研究结果表明，在紫外线范围内彻底消除反射会影响捕食者和猎物的感知，并最终改变猎物的行为。
