A long-standing goal for biologists and social scientists is to understand the factors that lead to the evolution and maintenance of co-operative behaviour between conspecifics. To that end, the fruit fly, Drosophila melanogaster, is becoming an increasingly popular model species to study sociality, however, most of the research to date has focused on adult behaviours. In this study, we set out to examine group feeding behaviour by larvae and to determine whether the degree of relatedness between individuals mediates the expression co-operation. In a series of assays, we manipulated the average degree of relatedness in groups of third instar larvae that were faced with resource scarcity, and measured the size, frequency and composition of feeding clusters, as well as the fitness benefits associated with co-operation. Our results suggest that larval D. melanogaster are capable of kin recognition (something that has not been previously described in this species), as clusters were more numerous, larger and involved more larvae, when more closely related kin were present in the social environment. These findings are discussed in the context of the correlated fitness-associated benefits of co-operation, the potential mechanisms by which individuals may recognize kin, and how that kinship may play an important role in facilitating the manifestation of this co-operative behaviour.

ASSAY_1Data from Experiment 1: Characterization of feeding clusters. This dataset contains measurements made on the number, size and membership of feeding clusters in vials of D. melanogaster where the degree of relatedness had been experimentally manipulated.ASSAY_2_SURVIVORSHIPData from Experiment 2: Assessing consequences of larval co-operative behaviour on survivorship and development. This dataset contains measurements made of the egg-to-adult survivorship of D. melanogaster where the degree of relatedness had been experimentally manipulated.ASSAY_2_WEIGHTSData from Experiment 2: Assessing consequences of larval co-operative behaviour on survivorship and development. This dataset contains measurements made of the weight of male and female of D. melanogaster that developed in vials where the degree of relatedness had been experimentally manipulated.ASSAY_3Data from Experiment 3: Measuring feeding cluster membership as it relates to kinship. This dataset contains the number of target (wild-type) and competitor (bw-eyed) adults eclosing from a sampled feeding cluster that was collected from a vial where the degree of relatedness between target larvae had been experimentally manipulated.