Phylogeny and acoustic signal evolution of a pure tone song katydid Pseudophyllus titan (Orthoptera: Tettigoniidae) based on the complete mitogenome

Abstract

Ensifera is an extremely diverse group in the order Orthoptera, and it has been the subject of considerable research, especially in terms of phylogeny and bioacoustics. Katydids are known for using high-frequency broadband signals whereas most cricket songs are pure tones with a frequency range of 2–8 kHz. Pseudophyllus titan is a special katydid emits low-frequency pure tone songs similar to that of crickets. Acoustic communication of Ensifera were widely studied, but song evolution could deserve new examination taking into account the newly available phylogenies. To examine the song evolution of P. titan in the Ensifera, the mitogenomes of P. titan and three other ensiferan species (Sphagniana ussuriana, Oecanthus sinensis, Truljalia hibinonis) were obtained by high-throughput sequencing. In addition, the phylogeny of Ensifera was reconstructed including 63 in-group taxa, and the divergence time was further estimated for major ensiferan lineages. Lastly, the evolutions of song frequency were evaluated based on an ancestral character state reconstruction (ACSR). Moreover, we have studied the calling songs of 78 katydids and performed ACSR based on five genes. All phylogeny analyses confirmed that the superfamily Schizodactyloidea was placed basally to the non-grylloid clade. P. titan was in the Pseudophyllinae clade, and this clade had a distant relationship form other lineages in Phaneropteridae. The ACSR showed that P. titan evolved low-frequency pure tone songs independently after ancestors of katydids evolved high-frequency broadband noise. Referring to the geologic time scale, we suggest that the song frequency evolution in the Ensifera to some extent caused by adaptations to the changing habitat under conditions of climate change and plant evolution.

KEYWORDS::

• Ensifera
• mitogenome
• phylogeny
• evolution
• insect song

Acknowledgments

We are grateful to J. Russell for improving the language of the manuscript and Dr. Pingxi Xu (Department of Molecular and Cell Biology, University of California, Davis) for valuable comments on an earlier version of the manuscript. We are also extremely grateful to other lab members for their participation in sample collection and song recording. The materials used in this work were supported by the Jilin Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, Changchun, China.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was funded by the Natural Science Foundation of China [No. 31501890, YLW], the Natural Science Foundation of Jilin Province [No. 20150101068JC and No. 20160204023NY, BZR; 20150520072JH, YLW], Foundation of Xinjiang Uygur Autonomous Region [No. 2017E0272] and the Open project program of the Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization [No. 130028684, BZR], Northeast Normal University.