A study on the bioacoustics of Oriental scaly crickets (Orthoptera: Mogoplistinae), with a focus on Singaporean species

ABSTRACT

The scaly crickets, Mogoplistinae, form a monophyletic group of crickets and are characterised by scales covering the integument. In many species, males have modified forewings for producing highly tonal calling songs. Despite being a highly speciose and abundant group of orthopterans in tropical forests, data on their calling songs and studies on their bioacoustics remain scanty. In this study, we recorded and described the calling songs of seven sympatric scaly cricket species belonging to three genera—Cycloptiloides, Ectatoderus and Ornebius—from Singapore. We compared call structure and call parameters of syntopic species occurring together in the same locality within Singapore and found that syntopic congeners exhibit acoustic partitioning to avoid inter-specific competition for the acoustic space. We also found that calling songs can be highly varied among congeners and species from the same species groups. Finally, we also observed that syllable duration and peak frequency exhibit vastly different allometric relationships with body size. Larger scaly cricket species bear disproportionately longer syllable duration, but not differences in peak frequency.

KEYWORDS:

• Allometry
• calling song
• chirp
• frequency
• Mogoplistidae
• Southeast Asia

Acknowledgement

MKT thanks Siew Tin Toh for assistance in the acoustic recording. Permission for collecting material was granted by the National Parks Board (NP/RP18-064), Singapore.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The work was supported by the Wildlife Reserves Singapore Conservation Fund.