Department of Biology, St Olaf College, Northfield, MN, USA.
Proc Biol Sci. 2023 Aug 30;290(2005):20230775. doi: 10.1098/rspb.2023.0775. Epub 2023 Aug 16.
Receivers of acoustic communication signals evaluate signal features to identify conspecifics. Changes in the ambient temperature can alter these features, rendering species recognition a challenge. To maintain effective communication, temperature coupling-changes in receiver signal preferences that parallel temperature-induced changes in signal parameters-occurs among genetically coupled signallers and receivers. Whether eavesdroppers of communication signals exhibit temperature coupling is unknown. Here, we investigate if the parasitoid fly , an eavesdropper of cricket calling songs, exhibits song pulse rate preferences that are temperature coupled. We use a high-speed treadmill system to record walking phonotaxis at three ambient temperatures (21, 25, and 30°C) in response to songs that varied in pulse rates (20 to 90 pulses per second). Total walking distance, peak steering velocity, angular heading, and the phonotaxis performance index varied with song pulse rates and ambient temperature. The peak of phonotaxis performance index preference functions became broader and shifted to higher pulse rate values at higher temperatures. Temperature-related changes in cricket songs between 21 and 30°C did not drastically affect the ability of flies to recognize cricket calling songs. These results confirm that temperature coupling can occur in eavesdroppers that are not genetically coupled with signallers.
声音通讯信号的接收者会评估信号特征，以识别同种生物。环境温度的变化会改变这些特征，从而使得物种识别变得具有挑战性。为了保持有效的通讯，信号偏好的温度耦合（即接收者信号偏好与信号参数因温度而发生的变化同步）会在遗传上耦合的信号发送者和接收者之间发生。然而，是否存在偷听通讯信号的偷听者表现出温度耦合现象，目前尚不清楚。在这里，我们研究了一种寄生蝇，它是蟋蟀求偶鸣声的偷听者，是否表现出与温度相关的鸣声脉冲率偏好的耦合现象。我们使用高速跑步机系统，在三个环境温度（21、25 和 30°C）下记录对脉冲率（20 到 90 次/秒）变化的鸣叫声的行走声向反应。总行走距离、峰值转向速度、角度方向和声向性能指数随鸣声脉冲率和环境温度的变化而变化。声向性能指数偏好函数的峰值变得更宽，并在较高温度下向更高的脉冲率值转移。在 21 到 30°C 之间蟋蟀鸣声的温度相关变化并没有极大地影响蝇类识别蟋蟀求偶鸣声的能力。这些结果证实，在与信号发送者没有遗传耦合的偷听者中，确实会发生温度耦合现象。
