Data from: Short- and mid-wavelength artificial light influences the flash signals of Aquatica ficta fireflies (Coleoptera: Lampyridae)

Urbanization can radically disrupt natural ecosystems through alteration of the sensory environment. Habitat disturbances are predicted to favor behaviorally flexible species capable of adapting to altered environments. When artificial light at night (ALAN) is introduced into urban areas, it has the potential to impede reproduction of local firefly populations by obscuring their bioluminescent courtship signals. Whether individual fireflies can brighten their signals to maintain visibility against an illuminated background remains unknown. In this study, we exposed male Aquatica ficta fireflies to diffused light of varying wavelength and intensity, and recorded their alarm flash signals. When exposed to wavelengths at or below 533 nm, males emitted brighter signals with decreased frequency. This is the first evidence of individual-level light signal plasticity in fireflies. In contrast, long wavelength ambient light (≥ 597 nm) did not affect signal morphology, likely because A. ficta cannot perceive these wavelengths. These results suggest long wavelength lighting is less likely to impact firefly courtship, and its use in place of broad spectrum white lighting could augment firefly conservation efforts. More generally, this study demonstrates benefits of bioluminescent signal plasticity in a "noisy" signaling environment, and sheds light on an important yet understudied consequence of urbanization.

城市化可通过改变感官环境，从根本上扰乱自然生态系统。栖息地扰动被认为更青睐具备行为灵活性、能够适应环境改变的物种。当夜间人工光源（artificial light at night, ALAN）进入城市区域时，其可能通过掩盖萤火虫用于求偶的生物发光信号，阻碍当地萤火虫种群的繁殖。目前尚不清楚单个萤火虫能否增强自身信号亮度，以在受光照的背景中维持信号可见性。本研究将雄性费克水萤（Aquatica ficta）暴露于不同波长与强度的漫射光环境中，并记录其警戒闪光信号。当暴露于波长小于等于533纳米的光线时，雄性个体的信号亮度提升，但闪光频率降低。这是首次在萤火虫中发现个体层面的光信号可塑性证据。与之相反，长波长环境光（≥597纳米）未对信号形态产生影响，这可能是因为费克水萤无法感知此类波长的光线。上述结果表明，长波长照明对萤火虫求偶行为的影响更小，若用其替代广谱白光照明，或可助力萤火虫保护工作。更广泛而言，本研究证实了在"嘈杂"的信号环境中，生物发光信号可塑性的优势，并揭示了城市化进程中一项尚未得到充分研究的重要后果。