Compared ontogenesis of courtship song components of males from the sibling species, D. melanogaster and D. simulans.

The courtship song of Drosophila is known to be an important signal involved in sex and species recognition. It consists of pulse song and sine song, which have been studied in a quantitative way with different parameters. For the first time the setting of both components of the acoustic signaling is described and compared for males belonging to the sibling species D. melanogaster and D. simulans. At early ages, these two species share similar interpulse interval values but maturation establishes the species specificity of this character. For D. melanogaster the variations of several acoustic parameters take place in two successive periods, whereas for D. simulans the majority of the acoustic features does not change much with age. In D. melanogaster, copulation success seems to be linked to the maturation of the acoustic performance, which is not the case for D. simulans.