The social life of Drosophila melanogaster

In this review, we explore the social behavior of the fruit fly Drosophila melanogaster, integrating mechanistic, ecological and evolutionary perspectives. Despite its status as a major laboratory model organism, D. melanogaster’s social life remains generally underappreciated by biologists. Adult flies attract others to food sources through pheromone deposition, leading to group formation. Within these groups, males engage in competitive reproductive behaviors while females adopt complex mating patterns and lay eggs communally. Both sexes adapt their reproductive behaviors to early as well as current social experience. Communal egg-laying by females promotes larval group formation, with larvae cooperating to dig tunnels for protection and breathing while feeding. Aggregation is also visible at the pupal stage, suggesting a social dimension to the entire life cycle of this species. We examine the competitive and cooperative behaviors of D. melanogaster, considering the ecological context (resource distribution, predation, parasitism pressures, and reproductive strategies) that influences these social interactions. We also discuss how individual behavior and physiology varies with group size and diversity, potentially as an adaptation to the costs and benefits of being in a group. This review underscores the potential of fruit flies in advancing research on social interactions and dynamics, demonstrating their usefulness for the fields of sociality, evolution and social neurosciences.