Interaction between Consecutive Responses in a Hemileucid Moth, and the Evolution of Insect Communication

Abstract

MOTHS of the neotropical Saturnioid family Hemileucidae perform a special movement on assuming the resting position from any preceding activity, which has been termed ‘rocking’¹. It is rigidly co-ordinated, and consists of fast, rhythmic side-to-side oscillations of the entire animal. This movement is unique to the Hemileucidae, and appears to be a highly conservative character within that family, for it occurs in all species so far examined, irrespective of either size or mode of protective coloration². Its function, if any, is unknown, but it is not concerned with the sexual responses of either sex, nor do the moths possess any known non-sexual social behaviour. The strength of this response may be scored as the number of complete oscillations performed; an analysis has shown that the strength of rocking executed by unconstrained moths of the Brazilian species Automeris aurantiaca Weym. is related to the nature of the sequence of acts preceding it¹.