Predictors of host specificity among behavior-manipulating parasites.

Area of Science:

• Ecology
• Parasitology
• Evolutionary Biology

Background:

• Ecological niche breadth and resource specialization represent fundamental biological trade-offs.
• Manipulating parasites are often presumed resource specialists, but their host exploitation breadth remains poorly understood.
• Understanding parasite niche breadth is crucial for predicting host-parasite interactions.

Purpose of the Study:

• To investigate the determinants of host specificity in manipulating helminth parasites.
• To analyze how host and parasite factors influence the ecological niche breadth of parasites that manipulate host behavior.
• To assess the relationship between parasite traits and the range of hosts they can exploit.

Main Methods:

• Analysis of published records for 67 helminth species across 38 genera known to induce increased trophic transmission.
• Examination of host-parasite taxonomy, parasite location within the host, type of behavioral manipulation, and host debilitation.
• Quantification of host specificity using the mean taxonomic relatedness of manipulated hosts.

Main Results:

• Significant variation in host specificity was observed across different helminth taxa.
• Parasite location, level of host debilitation, and host type were significant predictors of host specificity.
• Manipulation involving the central nervous system led to more specialized host use compared to physiological debilitation.

Conclusions:

• Host specificity in manipulating parasites is not uniform and varies considerably.
• Parasite-induced behavioral changes and physiological impacts shape the parasite's ecological niche.
• Phylogenetic relatedness of hosts is a valuable metric for studying the complexity of parasite-host interactions.