Scientists thought butterflies were deaf until 1912 when the first butterfly ears were identified. Only in the past decade or so have researchers examined the anatomy and physiology of butterfly ears, which they are finding to be quite diverse and present in several butterfly species.
The latest discovery was made with the blue morpho butterfly (Morpho peleides), which dazzles with its bright-blue wing coloration when it flits about in its native Central and South America.
Scientists knew from relatively recent research that the morpho sports simple wing ears. In the new study, Kathleen Lucas of the University of Bristol in England and her colleagues were interested in the odd-looking hearing membrane that sits at the base of the blue morpho’s wing. The tympanal membrane, as it is called, is oval-shaped with a dome at its center that kind of resembles the yolk at the center of a fried egg, Lucas said.
Sound waves from, say, crackling leaves or a singing bird hit the membrane and get converted into nerve impulses by nearby sensory organs . Those impulses are picked up by nerve cells.