Conclusions
Through controlled quantitative experiments, we were able to disentangle
the impacts of temperature, host phenology, host resistance and host
offspring type (sexual vs asexual) on the timing of seasonal disease
outbreaks that are repeatedly observed in nature in a well-studied
host-parasite model system where host and parasite overwinter
separately. We provide several lines of evidence that parasite infection
is strongly driven by temperature, beyond the effects of temperature on
host development, and that this relationship is modified by host
resistance and offspring type. This work highlights the importance of
understanding how hosts and parasites may respond differently to
environmental changes and provides insight into the seasonality of
epidemics, particularly for parasites with free-living stages. It also
allows us to improve our predictions regarding the response of
infectious disease outbreaks to climate change.