The field crickets in Kauai offer a live demonstration evolution in action. In 1991, cricket numbers crashed as parasitoid flies (Ormia ochracea) located male calling crickets by sound and made them ...

"Eavesdroppers, like flies that listen in on cricket songs, show how some species develop incredible abilities to detect sounds or signals ... that some male Pacific field crickets were evolving ...

Soon after the flies were introduced, the wing shape of some male Pacific field crickets ... to specific sound frequencies, and how the flies reacted to the different cricket songs.