‘Un chant d'appel amoureux’: acoustic communication in moths

Abstract

Tympanal sound receptors in moths evolved in response to selective pressures provided by echolocating insectivorous bats. The presence of these ultrasound detectors also set the stage for the later evolution of ultrasonic courtship signals in the tympanate moth families. Male moths have repeatedly exploited the bat-detection mechanisms in females for the purpose of finding, identifying and obtaining mates. Ultrasonic courtship has been described in several members of the moth families Arctiidae, Noctuidae and Pyralidae, and ultrasound is predicted to play a significant role in the courtship of other tympanate moths including the Sphingidae, Lymantriidae, Notodontidae and Geometridae. Ultrasonic signals are involved in species recognition, in male-male competition for mates and in female mate-choice systems. Pre-existing motor systems, including those involved in bat defence, have also been exploited for the purpose of generating high-frequency courtship signals. Sound production mechanisms in moths include thoracic tymbals, tegular tymbals, alar castanets and genital stridulatory organs. Thus, in both their sensory and motor aspects, the weapons of bat/moth warfare have frequently evolved into components of courtship systems.