Data from: Experience modulates an insect's response to anthropogenic noise

In response to anthropogenic noise, vertebrates express modified acoustic communication signals either through individual plasticity or local population adaptation. In contrast, how insects respond to this stressor is poorly studied. Field crickets Gryllus bimaculatus use acoustic signals to attract and locate mates and are commonly found in noisy roadside environments, offering a powerful system to study the effects of anthropogenic noise on insect communication. Rapid repetition of sexual calls (chirps) is essential to attract females, but calling incurs energetic costs and attracts predators. As a result, males are predicted to reduce calling rates when background noise is high. Here, we combine observations and experimental playbacks to show that the responses of Field cricket males to anthropogenic noise also depend on their previous experience with passing cars. First, we show that males living on highway edges decrease their chirp rate in response to passing cars. To assess whether this behavioural response depends on previous exposure to car noise, we then broadcast recordings of car noise to males located at different distances from the road and, therefore, with different previous exposure to car noise. Although all tested individuals responded to broadcasted traffic noise, males closest to the road decreased their chirp rate less than individuals calling further from the road. These results suggest that regular exposure to anthropogenic noise may decrease individuals' sensitivity and behavioural responses to noise, allowing them to maintain effective signalling rates. Behavioural plasticity modulated by experience may thus allow some insect species to cope with human-induced environmental stressors.

面对人为噪声，脊椎动物可通过个体可塑性或种群本地适应调整其声学通讯信号。与之相对，学界对昆虫如何响应这一环境胁迫的研究仍较为匮乏。双斑蟋（Gryllus bimaculatus）依靠声学信号吸引、定位配偶，且常出没于嘈杂的路边环境中，是研究人为噪声对昆虫通讯影响的理想模型体系。雄性快速重复的求偶鸣唱（鸣声）是吸引雌蟋的关键，但鸣唱会消耗大量能量，同时还会招来天敌。因此理论上，当背景噪声较高时，雄性会降低鸣唱速率。本研究结合野外观察与实验回放实验，证明双斑蟋雄性对人为噪声的响应，还取决于其过往遭遇过往车辆噪声的经历。首先，我们发现栖息于公路边缘的雄性双斑蟋，在遭遇过往车辆时会降低其鸣唱速率。为验证该行为响应是否依赖于此前的车辆噪声暴露经历，我们向距离公路远近不同、因而过往车辆噪声暴露程度各异的雄性双斑蟋，播放车辆噪声录音。尽管所有受试个体均对播放的交通噪声产生了响应，但距离公路最近的雄性，其鸣唱速率下降幅度反而低于远离公路的雄性个体。上述结果表明，定期暴露于人为噪声环境中，可能会降低个体对噪声的敏感度与行为响应程度，使其能够维持有效的信号传递频率。因此，经过往经历调控的行为可塑性，或可帮助部分昆虫类群应对人类活动引发的环境胁迫。