"The paired tymbals of a cicada are located on the sides of the abdominal base. The "singing" of a cicada is not stridulation as in many other familiar sound-producing insects like crickets (where one structure is rubbed against another): the tymbals are regions of the exoskeleton that are modified to form a complex membrane with thin, membranous portions and thickened "ribs". These membranes vibrate rapidly, and enlarged chambers derived from the tracheae make the cicada's body serve as a resonance chamber, greatly amplifying the sound. Some cicadas produce sounds louder than 106 dB (SPL), among the loudest of all insect-produced sounds. They modulate their noise by positioning their abdomens toward or away from the substrate."
Saturday, August 24, 2019
Posted by L. G. William Chapman, B.A., LL.B.