Bush Alex A, Yu Douglas W, Herberstein Marie E
School of Biological Sciences, University of East Anglia, Norwich, Norfolk, UK.
Proc Biol Sci. 2008 Jun 7;275(1640):1337-42. doi: 10.1098/rspb.2008.0062.
There are two major competing explanations for the counter-intuitive presence of bright coloration in certain orb-web spiders. Bright coloration could lure insect prey to the web vicinity, increasing the spider's foraging success. Alternatively, the markings could function as disruptive camouflage, making it difficult for the insect prey to distinguish spiders from background colour variation. We measured the prey capture rates of wasp spiders, Argiope bruennichi, that were blacked out, shielded from view using a leaf fragment, or left naturally coloured. Naturally coloured spiders caught over twice the number of prey as did either blacked-out or leaf-shielded spiders, and almost three times as many orthopteran prey. Spectrophotometer measurements suggest that the bright yellow bands on the spider's abdomen are visible to insect prey, but not the banding on the legs, which could disguise the spider's outline. Thus, our results provide strong support for the hypothesis that bright coloration in the wasp spider acts as a visual lure for insect prey and weak support for the hypothesis that the arrangement of the banding pattern across the spider's body disguises the presence of the spider on the web.
对于某些圆蛛身上出现的与直觉相悖的鲜艳色彩，有两种主要的相互竞争的解释。鲜艳的色彩可能会将昆虫猎物吸引到蛛网附近，提高蜘蛛的觅食成功率。或者，这些斑纹可能起到扰乱性伪装的作用，使昆虫猎物难以将蜘蛛与背景颜色变化区分开来。我们测量了被涂黑、用叶片碎片遮挡使其不可见或保持自然颜色的黄蜂蜘蛛（Argiope bruennichi）的猎物捕获率。自然颜色的蜘蛛捕获的猎物数量是被涂黑或被叶片遮挡的蜘蛛的两倍多，捕获的直翅目猎物数量几乎是它们的三倍。分光光度计测量表明，蜘蛛腹部的亮黄色条纹对昆虫猎物可见，但腿部的条纹则不然，腿部条纹可能会掩盖蜘蛛的轮廓。因此，我们的结果为黄蜂蜘蛛身上的鲜艳色彩作为对昆虫猎物的视觉诱饵这一假设提供了有力支持，而对蜘蛛身体上条纹图案的排列能掩盖其在蛛网上的存在这一假设的支持力度较弱。
