It is well known that female adults of frog-biting midges (Corethrellidae) are attracted by anuran mating calls. However, the role of host-emitted cues other than mating calls in determining the level of attraction remains poorly understood. Here, we performed field playback experiments to test how the host-seeking behaviour of Corethrella Coquillett is influenced by different sound stimuli: mating call of a tree frog, cricket call, and no sound. Then, after long-distance host detection, we evaluated if Corethrella can distinguish landing sites by using at short distance the colour and/or shape of anurans. For that, we placed artificial models of frogs with different colours (light green and dark brown) and an artificial caterpillar model (light green colour) on the top of speakers. We found that only frog mating calls presented with the visual cue of an artificial frog were attacked by Corethrella, suggesting that frog shape, regardless of colour, is an important cue for the identification of its hosts. This is the first study providing evidence that after flying long distances guided by frog calls, Corethrella can identify their hosts using visual cues at short distances.

中文翻译：

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不仅是听众：雌性蠓（Corethrellidae）也能分辨青蛙的形状

众所周知，蛙咬蠓 (Corethrellidae) 的雌性成虫会被无尾蠓的求偶叫声所吸引。然而，除交配呼叫外，宿主发出的线索在确定吸引力水平方面的作用仍然知之甚少。在这里，我们进行了现场回放实验，以测试科瑞拉Coquillett 受到不同声音刺激的影响：树蛙的求偶叫声、蟋蟀叫声和没有声音。然后，在远程主机检测之后，我们评估是否科瑞拉可以通过在短距离内使用无尾动物的颜色和/或形状来区分着陆点。为此，我们在扬声器顶部放置了不同颜色（浅绿色和深棕色）的人造青蛙模型和人造毛毛虫模型（浅绿色）。我们发现，只有带有人造青蛙视觉提示的青蛙求偶呼叫才会受到攻击。科瑞拉，表明青蛙的形状，无论颜色如何，都是识别其宿主的重要线索。这是第一项提供证据的研究，证明在青蛙叫声引导下长距离飞行后，科瑞拉可以使用短距离的视觉提示来识别它们的宿主。