Speaker
Description
Parasite virulence, the harm parasites cause to host survival and fitness, shapes host–parasite dynamics in both pathogenic and social parasites. Although high virulence can limit parasite persistence, outcomes depend on ecological context and can even lead parasites to function as net mutualists. Fungus-growing ants (Myrmicinae: Attini: Attina) form a well-studied symbiotic system that is vulnerable to exploitation by social parasites. While experiments have explored the mechanisms underlying these interactions, the theoretical conditions that allow multiple parasites to coexist on the same host remain unclear. Here, we develop a patch occupancy model inspired by fungus-growing ants to study a community in which multiple social parasites exploit a shared host. The model identifies conditions that allow the coexistence of both generalist and specialist parasites with their host at frequencies consistent with field observations. Our results show that context dependence, differences in parasite virulence, and the degree of specialization jointly explain coexistence patterns. We also determine when a less virulent parasite can function as a net mutualist rather than a parasite. Finally, we examine how species-specific dispersal strategies, reflected in different post-flight behaviors, influence coexistence in a spatially explicit setting.
