Trophic transmission of parasites and host behavior modification

Abstract

Thomas et al. (2005) provide a wide-ranging and insightful review of issues surrounding the evolution and ecology of parasite manipulation of host behavior. To support their goal seeking future directions I offer three comments. Firstly, several very different types of interactions are combined under the vague label “parasite”. This obscures important differences with respect to host behavior modification. These host–parasite interactions are pathogens, parasitoids, parasitic castrators and trophic a e s e o p t 2 f p p s a t the issue of adaptation since there is no countervailing host interest. However, they are of great interest as to mechanisms of host control with respect to the time and place of death (parasitoids), and longevity and risk aversive behavior (parasitic castrators). Pathogens may well modify host behavior, often to disseminate dispersal stages. For these interactions, issues of non-adaptive pathology and host defensive responses are highly relevant. Further, these behavior modifications are usually not complex, so sophisticated