Fig. 3: Experimental estimates of key fitness components for the best model, and the consequences of these estimates for pathogen infection rates for both morphotypes across Douglas-fir and grand fir.

Estimates for the multi-capsid morphotype are in blue and the single-capsid morphotype are in orange. A Estimates of the average infectiousness \(\overline{\nu }\) and the variation in infectiousness C for each morphotype on each tree species from the best Bayesian hierarchical model fit to the transmission field experiment data (N = 92). Data are shown as the mean of the posterior distribution (points) and error bars represent the 25th and 75th percentiles of the posterior distribution as calculated using the summary R function on the stanfit object. B Differences in morphotype infection rates as a function of initial host density (insects/m²) when only one morphotype is present in a single-season epizootic in a forest consisting of a single tree species; solid lines show the resulting fraction infected from simulations using the mean values for \(\overline{\nu }\) and C from A, while the shaded ribbon represents the 25th to 75th percentiles of the resulting fraction infected from simulations using the thinned posterior distribution of parameter sets (N = 225). Source data are provided as a Source Data file.