Chalkbrood: epidemiological perspectives from the host-parasite relationship.

Chalkbrood is a fungal brood disease of the honey bee, Apis mellifera, caused by the parasite Ascosphaera apis. Considered as a stress-related disease, the severity of chalkbrood outbreaks depend on a multitude of interacting factors. The specific relationship between host and parasite in this disease is interesting because the parasite is both heterothallic and semelparous. Recent studies highlight that this specific host-parasite relationship is influenced by factors such as interactions with other parasite strains or species, and environmental perturbations. To understand how to protect pollinators most effectively, it is crucial that future research takes a more ecologically relevant approach by studying the basic biology of the host-parasite relationship in the context of the multi-factorial processes that influence it.