Wingbeat-generated ultrasound in noctuid moths increases the discharge rate of the bat-detecting A1 cell

Abstract

Some noctuid moths produce ultrasound in flight as a consequence of contact between the distal margins of the hindwings. The sound produced from a conspecific 10 mm from the subject increases the discharge rate of the moth’s A1 acoustic cell which functions primarily to detect the echolocation calls of bats. Wingbeat sounds are largely ultrasonic, and may provide background noise through which the moth must recognize bat echolocation calls. The sounds may also limit the lower sensitivity of the auditory system. Wingbeat sounds produced appear to be mismatched to the low-frequency hearing of bats which hunt by passive listening, and are unlikely to be a significant aid to passive aerial foraging by bats.