Fiddler on the Tree - A Bush-Cricket Species with Unusual Stridulatory Organs and Song
Insects of the order Orthoptera are well-known for their acoustic communication. The structures used for this purpose show a high diversity which obviously relates to differences in song parameters and to the physics of sound production. Here we describe song and morphology of the sound producing organs of a tropical bush-cricket, Ectomoptera nepicauda, from East Africa. It has a very unusual calling song consisting of frequency-modulated, pure-tone sounds in the high ultrasonic range of 80 to120 kHz and produced by extremely fast wing movements. Concerning morphology, it represents the most extreme state in the degree of left-right fore-wing differentiation found among Orthoptera: the acoustic parts of the left fore-wing consist exclusively of the stridulatory file, comparable in function to the bow of a violin, while the right wing carries only the plectrum ( =  string) and mirror ( =  soundbox).
Shrinking Wings for Ultrasonic Pitch Production: Hyperintense Ultra-Short-Wavelength Calls in a New Genus of Neotropical Katydids (Orthoptera: Tettigoniidae)
This article reports the discovery of a new genus and three species of predaceous katydid (Insecta: Orthoptera) from Colombia and Ecuador in which males produce the highest frequency ultrasonic calling songs so far recorded from an arthropod. Male katydids sing by rubbing their wings together to attract distant females. Their song frequencies usually range from audio (5 kHz) to low ultrasonic (30 kHz). However, males of Supersonus spp. call females at 115 kHz, 125 kHz, and 150 kHz. Exceeding the human hearing range (50 Hz–20 kHz) by an order of magnitude, these insects also emit their ultrasound at unusually elevated sound pressure levels (SPL). In all three species these calls exceed 110 dB SPL rms re 20 µPa (at 15 cm). Males of Supersonus spp. have unusually reduced forewings (<0.5 mm2). Only the right wing radiates appreciable sound, the left bears the file and does not show a particular resonance. In contrast to most katydids, males of Supersonus spp. position and move their wings during sound production so that the concave aspect of the right wing, underlain by the insect dorsum, forms a contained cavity with sharp resonance. The observed high SPL at extreme carrier frequencies can be explained by wing anatomy, a resonant cavity with a membrane, and cuticle deformation.
Ultrasonic communication in Corcyra cephalonica (Stainton) (Lepidoptera: Pyralidae)
Male Corcyra cephalonica (Stainton) produce trains of 125 kHz sound pulses with a striated tymbal located on each tegula. There are nine striae on each tymbal making possible 36 sound pulses during each pulse train. The tymbals are activated by downward pressure of the forewings against the tegular-wing coupler. The sound is produced in two temporal patterns—a slow phase and a buzz phase. The sound produced by a calling male affects the behavior of both male and female C. cephalonica. It may also play a defensive role against other moth species competing with C. cephalonica for the same food resource. C. cephalonica infestations can be discovered and located by detecting male sound. Males can be accurately separated from females either by the presence of sound in living specimens or the presence of striated tymbals on dead specimens.