Authors
  • Northcott, Mark
  • Fullard, James H.
Universities
  • University of Toronto

Summary

The dogbane tiger moth, Cycnia tenera, emits ultrasonic sounds by rhythmically buckling a pair of tymbals when stimulated by pulsed sounds resembling bat echolocation. We monitored the central pattern generator governing this response by recording the motor output of the tymbal branch of the metathoracic leg nerve. The rhythm of the tymbal motor pattern can be altered midway (500 m/sec from its initiation) by changing the period and, to a lesser degree, the intensity of the stimulus. The tymbal response of C. tenera is therefore closed-looped to stimulus pulse period and intensity. Our results suggest that C. tenera relies less on the changes in an attacking bat's echolocation intensity when responding with this behaviour because this acoustic parameter may be a more unreliable indicator of the proximity of the bat than its echolocation call period.

Methodology

Collected eggs from QUBS, reared, acoustic stimuli, neural recordings