Sexual selection on cuticular hydrocarbons of male sagebrush crickets in the wild

Cuticular hydrocarbons (CHCs) play an essential role in mate recognition in insects but the form and intensity of sexual selection on CHCs has only been evaluated in a handful of studies, and never in a natural population. We quantified sexual selection operating on CHCs in a wild population of sagebrush crickets, a species in which nuptial feeding by females imposes an unambiguous phenotypic marker on males. Multivariate selection analysis revealed a saddle-shaped fitness surface, suggesting a complex interplay between the total abundance of CHCs and specific CHC combinations in their influence on female choice. The fitness surface resulting from two axes of disruptive selection reflected a trade-off between short- and long-chained CHCs, suggesting that males may be sacrificing some level of desiccation resistance in favour of increased attractiveness. There was a significant correlation between male body size and total CHC abundance, suggesting that male CHCs provide females with a re...表皮碳氢化合物（Cuticular hydrocarbons, CHCs）在昆虫的配偶识别中发挥着不可或缺的作用，但目前针对CHCs所承受的性选择形式与强度，仅在少量研究中得到评估，且从未在自然种群中开展过相关探究。我们在山艾树蟋蟀（sagebrush crickets）的野生种群中，量化了作用于CHCs的性选择——该物种的雌性婚饲行为会为雄性留下明确的表型标记。多变量选择分析揭示出鞍形适合度曲面，表明CHCs的总丰度与特定CHC组合在影响雌性选择方面存在复杂的相互作用。由两条歧化选择轴构成的适合度曲面，反映了短链与长链CHCs之间的权衡关系，提示雄性或许以牺牲一定程度的抗干燥性为代价，来提升自身的交配吸引力。雄性体型大小与CHC总丰度之间存在显著相关性，这表明雄性CHCs可为雌性提供……