Cicada Mate Attraction
Male cicadas are quite different to other singing insects and use a sound maker called a tymbal, which is located below each side of the anterior abdominal section [7]. Tymbals are exoskeleton structures that create complex membranes, thinly portioned, as well as thickened ribs. With the use of the tensor muscle, tightening of internal muscles buckles the tymbals inwards, creating a clicking noise, when the muscles then relax and the tymbals return outwards, another click is produced [18]. Sound is generated by rapidly vibrating the distorting membranes, combing the clicking into continuous notes [17].
|
This sound is echoed, as the abdomen of the cicada is mainly hollow, acting as a sound box. The song of the cicada is modulated via the abdomens position around substrates. Each species can produce its very own distinctive song, ensuring appropriate attraction, due to the pattern in which the clicks are combined [12]. In order to amplify their song the cicada have an adapted tracheal system which is compartmentalised into internal air sacs that allow the sound to resonate [7]. As mentioned males are the only sex to produce the cicada song, although both females and males have a membranous structure, the tympana, which detects sounds, being the equivalent of an ear. The male cicadas have the ability to disable their own tympana while singing, in order to prevent hearing damage [14].