Reverse stridulatory wing motion produces highly resonant calls in a neotropical katydid (Orthoptera: Tettigoniidae: Pseudophyllinae)

► Ischnomela gracilis produces sound during opening stroke of the wings and not during the closing as most Ensifera. ► The stridulatory file and scraper exhibit significant adaptation for a reverse scraper motion. ► Sound-radiating wing cells are sharply tuned to 15 kHz. ► During sound production, the scraper strikes nearly 15,000/s. ► Sound is produced in a reverse manner using resonance.