FIGURE 2.

Variation among hosts in different metrics of host quality. Effects of host species on (a) shedding of West Nile virus by birds four days after experimental inoculation (Komar et al., 2003); (b) spore production by Phtyphthorum ramorum, the causative agent of Sudden Oak Death, in woody plants (Rosenthal et al. 2020); (c) the proportion of ticks infected with Anaplasma phagocytophilum, the causative agent of human anaplasmosis, after feeding on mammals and birds (Keesing et al., 2012); (d) feeding success for Culex nigripalpis mosquitoes (Edman et al., 1974); and (e) molting success of blacklegged ticks (Ixodes scapularis) (Brunner et al., 2011). Data in (d) are the mean of eight observations of feeding by 200 female mosquitoes on two individuals of each host species; other sample sizes are indicated on bars. Characterizing the amount of variation across hosts is an important frontier (see main text), particularly how it varies for different types of disease systems, and how those patterns influence dilution effects