Bioacoustics of a miniature cricket, Cycloptiloides canariensis (Orthoptera: Gryllidae: Mogoplistinae)

Abstract

Male crickets, Cycloptiloides canariensis (body length 5 mm), stridulate with their forewings, which are hidden during rest under the large shield-like pronotum. The wings are opened into the stridulatory position by bending the body between the pro- and mesothorax. The song is a 2 s trill composed on average of 260 pulses (syllables) with a carrier frequency of about 6 kHz. The sound-emitting structures on the wings have been studied by laser vibrometry and particle dusting. A distinct membrane area, which includes a prominent mirror cell, acts as a resonator, amplifying the fundamental carrier frequency produced by interactions between the file and plectrum. The resonating membrane is extremely thin (mirror cell thickness 0.2 µm), which is a physical requirement for maintaining the carrier frequency in the cricket-specific range. Covering the wings after singing is probably an adaptation to protect these delicate structures from damage by mechanical contact during social interactions, especially mating.