The calling songs of some katydids (Orthoptera, Tettigonioidea) from the tropical forests of Southeast Asia

By

Tan, Ming Kai
Duncan, Jacob
Wahab, Rodzay Bin Haji Abdul
Lee, Chow-Yang
Japir, Razy
Chung, Arthur Y. C.
Baroga-Barbecho, Jessica B.
Yap, Sheryl A.
Montealegre-Z, Fernando

Type

Article

Date of Publication

2023-1-16

Original Publication

Journal of orthoptera research : JOR

Volume

32

Series / Issue

Issue: 1

Pages

1--24

Subjects

ACOUSTICS , calls , frequency , sound-producing organs , stridulation , Tettigoniidae , ultrasound

Contributed by

Pensoft Publishers

Language

English

Published by

Philadelphia, Penn Orthopterists' Society 1992-

Identifiers

DOI: https://doi.org/10.3897/jor.32.84563

 

Abstract

Katydids produce sound for signaling and communication by stridulation of the tegmina. Unlike crickets, most katydids are known to sing at ultrasonic frequencies. This has drawn interest in the investigation of the biophysics of ultrasonic sound production, detection, evolution, and ecology (including predator–prey interactions) of these katydids. However, most of these studies are based on species from the Neotropics, while little is known about katydid species from the hyperdiverse region of Southeast Asia. To address this, a concerted effort to document, record, and describe the calling songs of Southeast Asian katydids, especially species that call at ultrasonic frequencies, was made. A study spanning two years (2018–2020) in the Malay Peninsula (Singapore and Malaysia), Borneo (Brunei Darussalam and Sabah), and the Philippines revealed previously unknown calls of 24 katydid species from four subfamilies. The calling songs of Southeast Asian katydid species are highly diversified in terms of time and frequency. Call structure can range from isolated syllables (e.g., Holochlora), continuous trills (e.g., Axylus philippinus), to short pulse-trains (e.g., Euanisous teuthroides) and complex echemes (e.g., Conocephalus spp.), with 87.5% of species having ultrasonic peak frequencies and 12.5% being considered extreme ultrasonic callers (peak frequency >40 kHz). The call spectrum ranges from tonal (e.g., spectral entropy is 6.8 in Casigneta sp. 2) to resonant (entropy is 8.8 in Conocephalus cognatus). Of the 24 species whose calls are described here, we imaged and described the sound-producing structures of 18. This study provides a preliminary overview of the acoustic diversity of katydids in Southeast Asia, and the authors hope to inspire further investigation into the bioacoustics of little-known katydids from these areas. Amassing a database of calling songs and sound-producing organ illustrations from different species is important to address taxonomic impediments while advancing our knowledge about the bioacoustics of Southeast Asian katydids.