Kin recognition and co‐operative foraging in Drosophila melanogaster larvae

• Published in: Journal of evolutionary biology 2019-12, Vol.32 (12), p.1352-1361
• Main Authors: Khodaei, Lucas, Long, Tristan A. F.
• Format: Article
• Language: English
• Subjects: altruism; Clusters; Conspecifics; co‐operation; Drosophila melanogaster; Feeding; Feeding behavior; feeding clusters; Fitness; Fruit flies; group foraging; Insects; Kin recognition; kin selection; Larvae; Maintenance; Recognition; Reproductive fitness; social behaviour; Social environment
• ISSN: 1010-061X; 1420-9101
• DOI: 10.1111/jeb.13531

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. Drosophila melanogaster 3rd instar larvae working together in a 'feeding cluster' to access otherwise inaccessible resources. More closely‐related larvae are more likely to engage in this co‐operative behaviour with evolutionary benefits in increase weight and fecundity.