Aggression is a fundamental, innate part of animal behavior, prevalent throughout the animal kingdom. The outcome of successful aggressive encounters can endow individuals with increased social status, as well as access to territory, resources, and potential mates. Roughly, aggression in Drosophila males is modulated by the olfactory receptors Or67d and Or65a, which regulate the acute and chronic levels of aggressive arousal. Female Drosophila aggression, on the other hand, is not well understood. In this study, we introduce a novel context that reliably induces female aggression: by placing two females with a male we have been able to consistently observe aggression between the uncopulated female and the copulating pair. Using this simple assay we show that female aggression also requires olfaction. The aggressive display is at least partially dependent on activity of Or47b neurons, which detects fly-produced odorants. Interestingly, activity of Or67 neurons does not play a role in female aggression in this context. Additionally, the presence of food odor stimulates females to be more aggressive. Finally, we show that both mated and uncourted females display significantly less aggression, demonstrating that both external stimuli and internal states modulate female aggressive behavior.

This work was supported by Fundação para a Ciência e a Tecnologia (FCT, PD/BD/105943/2014)