Listening in pheromone plumes: Disruption of olfactory-guided mate attraction in a moth by a bat-like ultrasound

In English Nocturnal moths often use sex pheromones to find mates and ultrasonic hearing to evade echolocating
bat predators. Male moths, when confronted with both pheromones and sound, thus have to trade off
reproduction and predator avoidance depending on the relative strengths of the perceived conflicting
stimuli. The ultrasonic hearing of Plodia interpunctella was investigated. A threshold curve for evasive
reaction to ultrasound of tethered moths was established, and the frequency of best hearing was found
to be between 40 and 70 kHz. Flight tunnel experiments were performed where males orienting in a sex
pheromone plume were stimulated with 50 kHz pulses of different intensities. Pheromone-stimulated
males showed increased defensive response with increased intensity of the sound stimulus, and the
acoustic cue had long-lasting effects on their pheromone-mediated flight, revealing a cost associated
with vital evasive behaviours.