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

AbstractEnsifera 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 eva...