A scenario for the evolution of selective egg colouration: the roles of enemy-free space, camouflage, thermoregulation, and pigment limitation

Behavioural plasticity can drive the evolution of new traits in animals. In oviparous species, plasticity in oviposition behaviour could promote the evolution of new egg traits by exposing them to different selective pressures in novel oviposition sites. Individual females of the predatory stink bug Podisus maculiventris are able to selectively colour their eggs depending on leaf side, laying lightly pigmented eggs on leaf undersides and more pigmented eggs, which are more resistant to ultraviolet (UV) radiation damage, on leaf tops. Here, we propose an evolutionary scenario for P. maculiventris egg pigmentation and its selective application. We experimentally tested the influence of several ecological factors that: (i) could have favoured a behavioural shift towards laying eggs on leaf tops and thus the evolution of a UV-protective egg pigment (i.e. exploitation of enemy-reduced space or a thermoregulatory benefit) and (ii) could have subsequently led to the evolution of selective pigm...

行为可塑性可推动动物新性状的演化。在卵生（oviparous）物种中，产卵行为的可塑性可通过使卵暴露于新型产卵位点的不同选择压力之下，进而推动卵相关新性状的演化。捕食性蝽类斑腹刺益蝽（Podisus maculiventris）的雌性个体可根据叶片朝向选择性地为卵着色：在叶背产下色素沉着较浅的卵，而在叶面产下色素沉着更深的卵——这类深着色卵对紫外线（UV）辐射损伤具有更强的抗性。本研究针对斑腹刺益蝽的卵着色行为及其选择性应用提出了一套演化假说。我们通过实验测试了多种生态因子的影响，这些因子可能：(i) 推动产卵行为向叶面产卵的方向转变，进而演化出具备紫外线防护功能的卵色素（即利用天敌缩减空间或获得体温调节收益）；以及(ii) 后续推动选择性着色行为的演化，而