Uploaded August 2025 | Updated September 2026, 1 hour ago
Rohini Balakrishnan
Abstract Title: Predation risk of acoustic and vibratory signalling in a multimodally duetting katydid
Co-Authors: Kunjan Joshi; Kasturi Saha
Author affiliations: Centre for Ecological Sciences, Indian Institute of Science; Ashoka University
Abstract: Males of many katydid species use long-distance acoustic signals to attract conspecific females for mating. Females typically walk or fly towards signalling males. In the false leaf canopy katydid Onomarchus uninotatus from the Western Ghats of Southern India, however, females reply to male calls using substrate vibrational signals produced by tremulation. Males then use these vibrational signals to localise females. Thus both males and females signal as well as search in this multimodally duetting species. This provides us with the opportunity to test the sex-specific risks of signalling and searching in the same species. We carried out playback experiments as well as with live bat predators and katydid prey to evaluate the relative predation risk of acoustic and vibrational signalling, and of searching by walking and flying. We found that vibrational signalling was safe from bat approaches as compared with acoustic calling but, interestingly, walking was equally safe. Flying was the most risky behaviour. Bat predation thus selects against flight during mate search but cannot explain the evolution of tremulatory signalling.
Rohini Balakrishnan
Abstract Title: Predation risk of acoustic and vibratory signalling in a multimodally duetting katydid
Co-Authors: Kunjan Joshi; Kasturi Saha
Author affiliations: Centre for Ecological Sciences, Indian Institute of Science; Ashoka University
Abstract: Males of many katydid species use long-distance acoustic signals to attract conspecific females for mating. Females typically walk or fly towards signalling males. In the false leaf canopy katydid Onomarchus uninotatus from the Western Ghats of Southern India, however, females reply to male calls using substrate vibrational signals produced by tremulation. Males then use these vibrational signals to localise females. Thus both males and females signal as well as search in this multimodally duetting species. This provides us with the opportunity to test the sex-specific risks of signalling and searching in the same species. We carried out playback experiments as well as with live bat predators and katydid prey to evaluate the relative predation risk of acoustic and vibrational signalling, and of searching by walking and flying. We found that vibrational signalling was safe from bat approaches as compared with acoustic calling but, interestingly, walking was equally safe. Flying was the most risky behaviour. Bat predation thus selects against flight during mate search but cannot explain the evolution of tremulatory signalling.
