The ongoing COVID-19 pandemic demonstrates the drawbacks of living socially; increased contact and high host density encourage the spread of disease in social groups, compared to those living solitary. Social interactions promote disease spread, but how do animal groups deal with the increased risk of epidemics? The goal of this proposal is to identify key factors governing disease management in groups, so as to enhance our understanding of how behavioural host defences and immunity evolve. In turn, this will help shed light on how group disease defences influence social evolution. This work is crucial as the importance of pathogens as a driver of social complexity and novel adaptations is still unclear. To achieve this goal, I will use a powerful genetically and genomically established insect model organism, the flour beetle (Tribolium castaneum), to manipulate group relatedness, size and structure, as well as epidemiological risk (pathogen species and infection stage). I will then explore how these factors influence group cohesion or dissolution. By using a combination of chemical analyses to identify disease cues and recognition profiles of healthy group members during a secondment, and bioinformatic approaches at my host institution, this project will also provide a detailed picture of the underlying olfactory circuits and genetic pathways behind disease management in groups. By combining behavioural, chemical and bioinformatic assays, this project will be able to address key gaps in our knowledge of group disease defence and will have a large impact on the fields of social evolution and behaviour. The transfer of knowledge at both institutions will significantly expand my technical skillset and allow me to development of my own, independent research niche. The data acquired and skills learnt during this project will be invaluable for applying for independent research positions after the fellowship.