ULTRASONIC SIGNALS IN THE DEFENSE AND COURTSHIP OF EUCHAETES EGLE DRURY AND E-BOLTERI STRETCH (LEPIDOPTERA, ARCTIIDAE)

Euchaetes egle Drury and E. bolteri Stretch produce ultrasound using p aired thoracic tymbal organs in both defensive and sexual contexts. Th e defensive ultrasound produced in response to tactile stimulation is fully characterized The sounds are sexually monomorphic and species sp ecific in the number of sound pulses produced during each flexion and relaxation of the tymbal, peak frequency, peak intensity, and duration of the interval between flexion and relaxation. Ultrasonic signals pl ay a role in the courtship of both species. Males produce ultrasound j ust prior to contact with females, and it is shown to be important to courtship success in E. egle. Ultrasonic courtship communication is ma pped on a recently proposed cladogram for the family Arctiidae. The us e of ultrasound in courtship has evolved on at least three occasions w ithin the family.