Otte Tobias, Hilker Monika, Geiselhardt Sven
Institute of Biology, Freie Universität Berlin, Haderslebener Str. 9, 12163, Berlin, Germany.
J Chem Ecol. 2018 Mar;44(3):235-247. doi: 10.1007/s10886-018-0934-4. Epub 2018 Feb 22.
The insect integument is covered by cuticular hydrocarbons (CHCs) which provide protection against environmental stresses, but are also used for communication. Here we review current knowledge on environmental and insect-internal factors which shape phenotypic plasticity of solitary living insects, especially herbivorous ones. We address the dynamics of changes which may occur within minutes, but may also last weeks, depending on the species and conditions. Two different modes of changes are suggested, i.e. stepwise and gradual. A switch between two distinct environments (e.g. host plant switch by phytophagous insects) results in stepwise formation of two distinct adaptive phenotypes, while a gradual environmental change (e.g. temperature gradients) induces a gradual change of numerous adaptive CHC phenotypes. We further discuss the ecological and evolutionary consequences of phenotypic plasticity of insect CHC profiles by addressing the question at which conditions is CHC phenotypic plasticity beneficial. The high plasticity of CHC profiles might be a trade-off for insects using CHCs for communication. We discuss how insects cope with the challenge to produce and "understand" a highly plastic, environmentally dependent CHC pattern that conveys reliable and comprehensible information. Finally, we outline how phenotypic plasticity of CHC profiles may promote speciation in insects that rely on CHCs for mate recognition.
昆虫体表覆盖着表皮碳氢化合物（CHCs），这些化合物既能抵御环境压力，又用于交流。在此，我们综述了关于塑造独居昆虫，尤其是植食性昆虫表型可塑性的环境和昆虫内部因素的现有知识。我们探讨了变化的动态过程，这些变化可能在数分钟内发生，但也可能持续数周，这取决于物种和环境条件。文中提出了两种不同的变化模式，即逐步变化和渐变。在两种不同环境之间切换（例如植食性昆虫更换寄主植物）会导致两种不同适应表型的逐步形成，而逐渐的环境变化（例如温度梯度）会引发众多适应性CHC表型的渐变。我们通过探讨在何种条件下CHC表型可塑性有益这一问题，进一步讨论了昆虫CHC谱表型可塑性的生态和进化后果。CHC谱的高可塑性可能是昆虫利用CHCs进行交流所面临的一种权衡。我们讨论了昆虫如何应对产生并“理解”一种高度可塑性、依赖环境的CHC模式这一挑战，这种模式要传达可靠且易懂的信息。最后，我们概述了CHC谱的表型可塑性如何可能促进依赖CHCs进行配偶识别的昆虫的物种形成。
