Sexual signals for the colour-blind: cryptic female mantids signal quality through brightness

1. Cryptic coloration may evolve in response to selective pressure imposed by predators, yet effective intraspecific communication may require some level of detectability. This creates a tension between the benefits of sexually selected visual traits and the predatory costs imposed by greater conspicuousness, and little is known about how this tension may be ameliorated in highly cryptic species. 2. We explore these competing demands in the false garden mantid Pseudomantis albofimbriata, a colour-blind and seemingly cryptic insect. We use reflectance spectrometry and receptor-noise modelling to characterize the conspicuousness of mantid body regions in the visual systems of mates (mantids), as well as potential predators (birds) and prey (bees). We then use condition manipulation and conspecific choice tests to further explore the colour traits of interest. 3. Based on visual modelling, we find that male mantids are inconspicuous to conspecifics, prey and predators – that is, they are c...1. 隐秘色（cryptic coloration）的演化通常是为了应对捕食者施加的选择压力，然而有效的种内通讯（intraspecific communication）往往需要一定程度的可探测性。这便在性选择视觉特征的益处与过度显眼带来的捕食代价之间形成了权衡矛盾，目前学界对如何在高度隐秘的物种中缓解这一矛盾仍所知甚少。2. 本研究以假花园螳螂（Pseudomantis albofimbriata）——一种色盲且外观看似具有隐秘性的昆虫——为研究对象，探究这两种相互竞争的需求。我们采用反射光谱测定法（reflectance spectrometry）与受体噪声建模（receptor-noise modelling），分别在配偶（螳螂自身）、潜在捕食者（鸟类）以及猎物（蜜蜂）的视觉系统中，表征螳螂身体各区域的显眼度。随后我们通过条件操控实验与同种选择实验，进一步探究目标颜色性状。3. 基于视觉建模结果，我们发现雄性假花园螳螂在同种个体、猎物与捕食者的视觉中均不显眼——亦即它们具