In the rainforests of South America, scientists have discovered a new genus and three new species of insect with the highest ultrasonic calling songs ever recorded in the animal kingdom. The insects have lost the ability of flight due to their reduced wing size, so the adoption of extreme ultrasonic frequencies might play a role in avoiding predators, such as bats.
Katydids (or bushcrickets) are insects known for their acoustic communication, with the male producing sound by rubbing its wings together (stridulation) to attract distant females for mating.
Scientists from the universities of Lincoln, Strathclyde and Toronto located a new genus with three new species of katydid in the rainforests of Colombia and Ecuador. These insects were found to produce the highest ultrasonic calling songs known in nature, with males reaching 150 kHz. The calling frequencies used by most katydids range between 5 kHz and 30 kHz. The nominal human hearing range ends at around 20 kHz. For this reason, the new genus has been named Supersonus.
Dr Fernando Montealegre-Z, from the School of Life Sciences, University of Lincoln, UK, said: "To call distant females, male katydids produce songs by 'stridulation' where one wing (the scraper) rubs against a row of 'teeth' on the other wing. The scraper is next to a vibrating drum that acts like a speaker. The forewings and drums are unusually reduced in size in the Supersonus species, yet they still manage to be highly ultrasonic and very loud."