Food web structure selects for parasite host range. Issue 1908 (14th August 2019)

• Record Type: Journal Article
• Authors: Park, A. W.
• Is Part Of: Proceedings. Volume 286:Issue 1908(2019)
• Publication Date: 2019-08-14
• Subjects: parasite specificity -- complex life cycle parasite -- trophic transmission -- food web -- diet breadth -- fitness cost; Biology -- Periodicals; 570.5
• DOI: 10.1098/rspb.2019.1277
• Languages: English
• ISSNs: 0962-8452

Abstract

Abstract : Complex life cycle parasites, including helminths, use intermediate hosts for development and definitive hosts for reproduction, with interactions between the two host types governed by food web structure. I study how a parasite's intermediate host range is controlled by the diet breadth of definitive host species and the cost of parasite generalism, a putative fitness cost that assumes host range trades off against fitness derived from a host species. In spite of such costs, a benefit to generalism may occur when the definitive host exhibits a large diet breadth, enhancing transmission of generalist parasites via consumption of a broad array of infected intermediate hosts. I develop a simple theoretical model to demonstrate how different host range infection strategies are differentially selected for across a gradient of definitive host diet breadth according to the cost of generalism. I then use a parasitic helminth–host database in conjunction with a food web database to show that diet breadth of definitive hosts promotes generalist infection strategies at the intermediate host level, indicating relatively low costs of parasite generalism among helminths.