Acoustic communication of the red‐haired bark beetle Hylurgus ligniperda

Abstract

AbstractBark beetles (Coleoptera: Curculionidae: Scolytinae) are a speciose subfamily of weevils that primarily live in bark and consequently largely communicate using sound. Having colonized multiple countries outside its native range, Hylurgus ligniperda (Fabricius) is considered to be a successful invader, yet little is known about its acoustic communication. In the present study, we investigate individual sound production and dyadic interactions among males and females of H. ligniperda. Two temporal parameters (duration and inter‐note interval) and three spectral parameters (minimum, maximum and centroid frequencies) are used as descriptors to quantify call variations depending on behavioural context. We also present a method for automatically extracting and analyzing these calls, which allows acoustic discrimination amongst individuals. Hylurgus ligniperda exhibits sexual dimorphism in its stridulatory organ. Females do not produce stridulatory sounds, whereas males produce single‐noted calls and modify their spectro‐temporal parameters in accordance with context. Acoustic stimulation from nearby males does not appear to be a causative factor in such modification. Instead, hierarchical clustering analysis shows that physical interactions play a more important role in affecting call parameters than acoustic signals. Centroid and maximum frequencies are the largest contributors to the variability of the data, suggesting that call variations in H. ligniperda mainly occur in the spectral domain.