title: Parasites in food webs: the ultimate missing links.
abstract: Parasitism is the most common consumer strategy among organisms, yet only recently has there been a call for the inclusion of infectious disease agents in food webs. The value of this effort hinges on whether parasites affect food-web properties. Increasing evidence suggests that parasites have the potential to uniquely alter food-web topology in terms of chain length, connectance and robustness. In addition, parasites might affect food-web stability, interaction strength and energy flow. Food-web structure also affects infectious disease dynamics because parasites depend on the ecological networks in which they live. Empirically, incorporating parasites into food webs is straightforward. We may start with existing food webs and add parasites as nodes, or we may try to build food webs around systems for which we already have a good understanding of infectious processes. In the future, perhaps researchers will add parasites while they construct food webs. Less clear is how food-web theory can accommodate parasites. This is a deep and central problem in theoretical biology and applied mathematics. For instance, is representing parasites with complex life cycles as a single node equivalent to representing other species with ontogenetic niche shifts as a single node? Can parasitism fit into fundamental frameworks such as the niche model? Can we integrate infectious disease models into the emerging field of dynamic food-web modelling? Future progress will benefit from interdisciplinary collaborations between ecologists and infectious disease biologists.
authors.affiliation: Western Ecological Research Center, U.S. Geological Survey. c/o Marine Science Institute, UC, Santa Barbara, CA 93106, USA. lafferty@lifesci.ucsb.edu
authors.forename: Kevin D
authors.initials: KD
authors.lastname: Lafferty
authors.forename: Stefano
authors.initials: S
authors.lastname: Allesina
authors.forename: Matias
authors.initials: M
authors.lastname: Arim
authors.forename: Cherie J
authors.initials: CJ
authors.lastname: Briggs
authors.forename: Giulio
authors.initials: G
authors.lastname: De Leo
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Dobson
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Dunne
authors.forename: Pieter T J
authors.initials: PT
authors.lastname: Johnson
authors.forename: Armand M
authors.initials: AM
authors.lastname: Kuris
authors.forename: David J
authors.initials: DJ
authors.lastname: Marcogliese
authors.forename: Neo D
authors.initials: ND
authors.lastname: Martinez
authors.forename: Jane
authors.initials: J
authors.lastname: Memmott
authors.forename: Pablo A
authors.initials: PA
authors.lastname: Marquet
authors.forename: John P
authors.initials: JP
authors.lastname: McLaughlin
authors.forename: Erin A
authors.initials: EA
authors.lastname: Mordecai
authors.forename: Mercedes
authors.initials: M
authors.lastname: Pascual
authors.forename: Robert
authors.initials: R
authors.lastname: Poulin
authors.forename: David W
authors.initials: DW
authors.lastname: Thieltges
mesh_terms: D000818:Animals; D004199:Disease Vectors; D020387:Food Chain; D006790:Host-Parasite Interactions; D007553:Isotope Labeling; D008954:Models, Biological; D010271:Parasites / Q000502:physiology*