How male signaling intensity influences phonotaxis in virgin female Jamaican field crickets (Gryllus assimilis)

Understanding female mate preference is important for determining the strength and the direction of sexual trait evolution. Male signalling intensity is often an important predictor of mating success because higher intensity (louder) signallers are detectable at greater distances. However, if females are simultaneously more attracted to higher signalling intensities, then the potential fitness impacts of higher intensity signalling should be elevated beyond what would be expected from detection distance alone. Here we manipulated the signal intensity of cricket mate attraction signals to determine how female phonotaxis was influenced. We examined female phonotaxis using two common methodologies: spherical treadmills and open arenas. Both methodologies showed similar results, with females exhibiting highest phonotaxis towards loud (X̅+1 SD = 69 dB) mate attraction signals but showing reduced phonotaxis towards the loudest (X̅+2 SD = 77 dB) signals. Reduced phonotaxis towards supernormal stimuli may occur for several reasons including elevating the females’ perceived predation risk, invoking females’ acoustic startle response, or exceeding females’ perceptual limits.