More than stridulation: signal interaction and constraint in the complex vibroacoustic courtship of a cricket

Abstract

Abstract Crickets (Gryllidae) produce sounds by tegminal stridulation, extensively studied for its role in female attraction and choice. However, their close-range courtship song, along with additional chemical, visual, and thermal signals, fails to clarify the observed female preferences. Beyond stridulation, crickets exhibit a range of vibrational courtship behaviours that remain largely unexplored. In this study, using Acheta domesticus as a model, we present the first comprehensive analysis of the entire set of vibroacoustic courtship signals in crickets, including their interaction. Employing audio recording, laser vibrometry, and videorecording, we unveil a complex signal involving simultaneous wing stridulation, body tremulation, and leg drumming against the substrate. These signal components exhibit a pattern of regular exchange within a specific time window relative to each other. We show the tightest coupling between the two types of stridulation pulses, and between tremulation and drumming signals, supported by the linear corelation of their rates. The coupling between drumming and stridulation signals is less consistent, with the non-linear corelation between their temporal and association parameters revealing a constraint on drumming performance. Yet, drumming is performed with high accuracy relative to stridulation, unrelated to its rate. Spectral-intensity analysis indicates the closest perceptual and thus functional connection between stridulation and drumming components of the complex signal, while proposing another function for tremulation unrelated to female choice. Our data demonstrate that the information conveyed by the complex courtship display in A. domesticus is not simply proportional to that in the song, potentially providing a much more reliable basis for female choice.