Variation in call types, calling activity patterns and relationship between call frequency and body size in a field cricket, Acanthogryllus asiaticus

ABSTRACT

In this study, we examined the temporal variation in calling activity of a field cricket, Acanthogryllus asiaticus on a diel and seasonal scale. We also examined the acoustic structure of calls produced in the context of mating, namely, long distance mating call (LDMC), courtship call and post copulatory call. Finally, we examined the allometric relationship between sound-producing structures and body morphometry and tested whether peak frequency of LDMC was indicative of male body size. Our findings suggest that calling activity of A. asiaticus peaked between 2100 and 2400 h on a diel scale and between March and May (summer) on a seasonal scale. The three calls were acoustically distinct and stereotypic with the courtship and post copulatory calls being composed of two chirp-types each. This study presents the first description of post copulatory calls of a field cricket. Morphometric analyses revealed that both inter-tooth distance and teeth width varied along the file length, however, number of teeth and file length were not correlated. Harp area was correlated with body size and peak frequency was significantly negatively correlated with harp area. This implies that the peak frequency can potentially be an indicator of body size in this species.

KEYWORDS:

• Seasonality
• diel activity
• allometry
• inter-tooth distance
• post copulatory call

Acknowledgements

We are grateful to Mr. Anindya Chaudhuri for contributing raw data for morphometry and peak frequency. We thank Mr. Anterjot Singh for helping with field work and Mr. Rohit Negi for helping with morphometry. We also gratefully acknowledge the two anonymous reviewers for giving useful comments that improved the manuscript.

Author contributions

MJ designed the study and RS collected the field and lab data and carried out the analyses with MJ’s help. MJ and RS wrote the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The data described in this article are openly available in the Open Science Framework at doi:10.17605/OSF.IO/TPA6U.

SUPPLEMENTARY MATERIALS

Supplemental data for this article can be accessed here.

Additional information

Funding

The research was supported by grants from Indian Institute of Science Education and Research Mohali to MJ and Innovation in Science Pursuit for Inspired Research (INSPIRE) Fellowship scheme by Department of Science & Technology, India, (https://online-inspire.gov.in/) [Grant no. DST/INSPIRE Fellowship/2014/IF140843] to RS.