Fig. 2.

Host association patterns under varied assumptions.

Note: The four panels show the (equilibrium) relative prevalence of parasite $A[IA/(IA+IB)]$ in both host species on the $y$-axis and the probability of disease-induced mortality on the $x$-axis. Dashed boxes represent parameter space leading to reciprocal host association. Roman numerals (panel A) indicate types of host association patterns described in the main text. Panel A illustrates no superinfection of $I2B(\epsilon =0)$ and no virulence cost for parasite $B(f=0)$. Panel B depicts $\epsilon =0.25$ and $f=0$. Panel C depicts $\epsilon =0$ and $f=0.25$. And panel D depicts $\epsilon =0.25$ and $f=0.25$. The basic superinfection rate $q$ is set to 0.1 for all panels. Note the relative prevalences indicate that high $A$ reflects low $B$, and low $A$ reflects high $B$. The $x$-axes show the probability of disease-induced mortality, defined as $v/(v+\mu )$.