tympanal organ

The tympanal organ is a sensory structure found in some insects that functions as an ear, allowing them to detect sound. These organs are typically located on the thorax or abdomen, though in mosquitoes, they are found on the head as part of the antennae.1

A tympanal organ consists of a thin, chitinous membrane (the tympanic membrane) and associated scolophores. When sound waves cause the tympanic membrane to vibrate, nerve fibers transmit impulses to the insect's central nervous system, enabling it to perceive sound. The complexity of these organs varies; simple ones in moths have only a few scolophores, while those in cicadas can have up to 1,500. Studies on grasshoppers, which have around 80-100 scolophores, show sensitivity to a range of frequencies, with maximum sensitivity typically between 3,000 and 5,000 hertz.12