Wee Jocelyn Liang Qi, Monteiro Antónia
Department of Biological Sciences, National University of Singapore, Singapore, Singapore.
Yale-NUS College, Singapore, Singapore.
PLoS One. 2017 Jan 6;12(1):e0168243. doi: 10.1371/journal.pone.0168243. eCollection 2017.
Butterflies of the South Asian and Australian genus Delias possess striking colours on the ventral wings that are presumed to serve as warning signals to predators. However, this has not been shown empirically. Here we experimentally tested whether the colours of one member of this diverse genus, Delias hyparete, function as aposematic signals. We constructed artificial paper models with either a faithful colour representation of D. hyparete, or with all of its colours converted to grey scale. We also produced models where single colours were left intact, while others were converted to grey-scale or removed entirely. We placed all model types simultaneously in the field, attached to a live mealworm, and measured relative attack rates at three separate field sites. Faithful models of D. hyparete, suffered the least amount of attacks, followed by grey-scale models with unaltered red patches, and by grey-scale models with unaltered yellow patches. We conclude that red and yellow colours function as warning signals. By mapping dorsal and ventral colouration onto a phylogeny of Delias, we observed that yellow and red colours appear almost exclusively on the ventral wing surfaces, and that basal lineages have mostly yellow, white, and black wings, whereas derived lineages contain red colour in addition to the other colours. Red appears to be, thus, a novel adaptive trait in this lineage of butterflies.
南亚和澳大利亚的黛眼蝶属蝴蝶，其翅腹面有着醒目的颜色，据推测这些颜色是用作对捕食者的警示信号。然而，这一点尚未得到实证证明。在此，我们通过实验测试了这个多样化属中的一个成员——黑脉黛眼蝶的颜色是否起到警戒信号的作用。我们制作了人工纸模型，一种是忠实地呈现黑脉黛眼蝶的颜色，另一种是将其所有颜色都转换为灰度。我们还制作了一些模型，其中单一颜色保持不变，而其他颜色转换为灰度或完全去除。我们将所有模型类型同时放置在野外，固定在一条活的黄粉虫上，并在三个不同的野外地点测量相对攻击率。黑脉黛眼蝶的忠实模型遭受的攻击最少，其次是带有未改变红色斑块的灰度模型，以及带有未改变黄色斑块的灰度模型。我们得出结论，红色和黄色起到了警示信号的作用。通过将翅背面和腹面的颜色映射到黛眼蝶的系统发育树上，我们观察到黄色和红色几乎只出现在翅腹面，而且基部谱系大多具有黄色、白色和黑色的翅膀，而衍生谱系除了其他颜色外还含有红色。因此，红色似乎是这个蝴蝶谱系中的一个新的适应性特征。
