Fig. 1. The sound-producing tymbal of the Australian cicada Cyclochila australasiae. (Top) Diagram showing the position of the tymbal (red arrow) at the anterior end of the insect's abdomen. (A) An unstained tymbal photographed in natural light (original). (B) A different tymbal stained for 24 hours in very dilute methylene blue solution (from Young and Bennet-Clark, 1993). (C) The tymbal shown in A showing fluorescence when illuminated by an ultra-violet light-emitting diode radiating at 365 nm; the fluorescence of the resilin is not as bright as if it had been radiated at the optimal wavelength, 315 nm (original).