Mating pair drives aggressive behavior in female Drosophila.

Aggression is an adaptive set of behaviors that allows animals to compete against one another in an environment of limited resources. Typically, males fight for mates and food, whereas females fight for food and nest sites. Although the study of male aggression has been facilitated by the extravagant nature of the ritualized displays involved and the remarkable armaments sported by males of many species, the subtler and rarer instances of inter-female aggression have historically received much less attention. In Drosophila, females display high levels of complex and highly structured aggression on a food patch with conspecific females. Other contexts of female aggression have not been explored. Indeed, whether females compete for mating partners, as males do, has remained unknown so far. In the present work, we report that Drosophila melanogaster females reliably display aggression toward mating pairs. This aggressive behavior is regulated by mating status and perception of mating opportunities and relies heavily on olfaction. Furthermore, we found that food odor in combination with OR47b-dependent fly odor sensing is required for proper expression of aggressive behavior. Taken together, we describe a social context linked to reproduction in which Drosophila females aspiring to mate produce consistent and stereotyped displays of aggression. These findings open the door for further inquiries into the neural mechanisms that govern this behavior.