Data from: 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 reliable cue for maximizing benefits obtained from males. Notwithstanding the conspicuousness of males’ acoustic signals, our results suggest that selection imposed on males via female mating preferences may be far more complex than previously appreciated and operating in multiple sensory modalities.

表皮碳氢化合物（Cuticular hydrocarbons, CHCs）在昆虫配偶识别过程中发挥着关键作用，但目前仅在少量研究中对作用于CHCs的性选择形式与强度进行了评估，且从未在自然种群中开展过此类研究。我们在一个野生灌丛蟋蟀种群中，对作用于CHCs的性选择开展了量化分析；该物种中，雌性的婚饲行为会为雄性留下明确的表型标记。多变量选择分析结果显示存在鞍形适合度曲面，这表明CHCs的总丰度与特定CHC组合在影响雌性配偶选择时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，反映出短链与长链CHCs之间存在权衡关系，提示雄性或许会牺牲一定的耐旱性，以换取更高的交配吸引力。雄性体型与CHC总丰度间存在显著相关性，这表明CHCs可为雌性提供可靠的信号，帮助其最大化从雄性处获得的收益。尽管雄性的声学信号十分醒目，但我们的研究结果表明，雌性交配偏好对雄性施加的选择压力，或许远比此前认知的更为复杂，且可通过多种感官模态发挥作用。