The arctiid, Cycnia tenera Hiibner exhibits no sexual dimorphism in six out of seven acoustic parameters measured in the sounds emitted by five male and five female specimens. The parameters reveal an extremely high level of variability for both male and female emissions. These observations suggest that calling or courtship signalling are not likely roles for the sounds of C. tenera but do not rule out the possibility of other intra specific communicative functions.
Specimens of C. tenera were collected from June 7 to July 17, 1975 from four ultraviolet light traps at the Queen's University Biological Station near Chaffey's Locks, Ontario, Canada. Moths were recorded immediately following capture. The specimens were placed individually 2 cm from a Briiel and Kjaer (B&K) 1/4-inch condenser microphone Type 4135 and stimulated to produce sounds by holding the moth's upraised wings between thumb and forefinger and lightly touching the insect's abdomen. It was possible, in this way, to obtain sustained emissions of up to 30 sec in length after the initial stimulus was applied. Sounds produced by moths restrained in this fashion appeared no different than those from specimens recorded in stationary flight with their wings free. The method employed in this study, however, did allow for greater accuracy of intensity measurements.