title: Variable prey development time suppresses predator-prey cycles and enhances stability.
abstract: Although theoretical models have demonstrated that predator-prey population dynamics can depend critically on age (stage) structure and the duration and variability in development times of different life stages, experimental support for this theory is non-existent. We conducted an experiment with a host-parasitoid system to test the prediction that increased variability in the development time of the vulnerable host stage can promote interaction stability. Host-parasitoid microcosms were subjected to two treatments: Normal and High variance in the duration of the vulnerable host stage. In control and Normal-variance microcosms, hosts and parasitoids exhibited distinct population cycles. In contrast, insect abundances were 18-24% less variable in High- than Normal-variance microcosms. More significantly, periodicity in host-parasitoid population dynamics disappeared in the High-variance microcosms. Simulation models confirmed that stability in High-variance microcosms was sufficient to prevent extinction. We conclude that developmental variability is critical to predator-prey population dynamics and could be exploited in pest-management programs.
authors.affiliation: Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, 70803, USA.
authors.forename: James T
authors.initials: JT
authors.lastname: Cronin
authors.affiliation: Department of Zoology, Southern Illinois University, Carbondale, Illinois, 62901, USA.
authors.forename: John D
authors.initials: JD
authors.lastname: Reeve
authors.affiliation: Department of Mathematics, Southern Illinois University, Carbondale, Illinois, 62901, USA.
authors.forename: Dashun
authors.initials: D
authors.lastname: Xu
authors.affiliation: Department of Mathematics, Southern Illinois University, Carbondale, Illinois, 62901, USA.
authors.forename: Mingqing
authors.initials: M
authors.lastname: Xiao
authors.affiliation: Department of Mathematics, Southern Illinois University, Carbondale, Illinois, 62901, USA.
authors.forename: Heidi N
authors.initials: HN
authors.lastname: Stevens
mesh_terms: D000818:Animals; D005260:Female; D020387:Food Chain; D006790:Host-Parasite Interactions; D008297:Male; D008954:Models, Biological; D014863:Wasps / Q000254:growth & development / Q000502:physiology*; D048889:Weevils / Q000254:growth & development / Q000469:parasitology* / Q000502:physiology*
keywords: Age-structured populations; developmental variability; host-parasitoid microcosms; intraspecific trait variability; population cycles; predator-prey stability