Ultrasound Communication in the Pyralid Moth Species Symmoracma minoralis (Lepidoptera: Pyralidae: Nymphulinae)

A typical characteristic of moth mate localization is the search by the male [M] for the female [F] who emits pheromones. MM of Symmoracma minoralis (Snellen 1879), however, were observed signalling acoustically from song perches. They almost continuously sing throughout the night, interrupting their song mainly for short flights, directed, at least in some cases, to calling MM in the neighborhood. MM and FF were found in copula on song perches, indicating that the F was attracted by the song. It is however possible that the song is also be used to establish male territories, since singing MM were generally found several meters apart. Rival songs and physical interactions between MM were also observed on song perches. These positions were occupied throughout the night and even over periods of several days, as a consequence of high site fidelity of MM as well as of the attractive spatial structure of some perches. The evolution of acoustical signalling in moths is discussed in relation to the costs of communication in MM and FF.