First record of an atypical and non-stridulatory sound produced by the larvae of two species of Dichotomius (Coleoptera: Scarabaeidae) from Argentina

ABSTRACT

The following study presents the first record of an atypical sound never reported before produced by the larvae of two species of dung beetles from Argentina, Dichotomius (Luederwaldtinia) carbonarius (Mannerheim 1829) and Dichotomius (Luederwaldtinia) nisus (Olivier 1789). This new sound is produced by the larvae in their three instars by shaking the third pair of legs inside the pupation chamber, which does not involve a stridulatory mechanism. Recorded sounds and video images of the larval behaviour are provided. The oscillograms, spectrograms and possible functions are analysed, and a new sound production mechanism is postulated.

KEYWORDS:

• bioacoustic
• coprophagous
• dung beetles
• larval behaviour
• neotropical

Acknowledgements

The authors thank Julián Baigorria (Karadya Bioreserve, Misiones); Horacio and Nahuel Schenone, Javier Unizoni (CIAR, Misiones – Fundación Bosques Nativos Argentinos para la Biodiversidad); Pablo Dinghi and Fabricio Rugnone for their assistance in the laboratory studies; Georgina del Fueyo and Martín Carrizo for lending us the stereomicroscope, Julian Clavijo-Bustos for providing collection information, Eliana Barona for helping us with submitting the larval sound to the Colección de Sonidos Ambientales (IAvH-CSA); members of the División Icnología (MACN) for their permanent support; and the Journal of the Entomological Society of India for providing us with a bibliography.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/00222933.2023.2256509.

Additional information

Funding

This work was supported by Agencia Nacional de Pormoción Científica y Tecnológica - FONCyT, PICT 2017–0779 to J. F. Genise.