Study Patterns
We identified substantial gaps in the literature reviewed for certain combinations of moderators (Table 2). In particular, no observational studies considered non-consumptive effects, and no studies that measured parasitism by intensity metrics or that studied macroparasites manipulated the effect of predator-spreaders. Both micro- and macroparasites are represented in studies measuring both prevalence and intensity but macroparasites were more common in intensity studies (n = 41/61) and microparasites more common in prevalence studies (n = 66/89). Both macro- and microparasites had the effects of both interaction types studied in fairly even proportions, but non-consumptive effects were more represented in macroparasite prevalence studies while they were more common in microparasite intensity studies.