title: Age structure changes and extraordinary lifespan in wild medfly populations.
abstract: The main purpose of this study was to test the hypotheses that major changes in age structure occur in wild populations of the Mediterranean fruit fly (medfly) and that a substantial fraction of individuals survive to middle age and beyond (> 3-4 weeks). We thus brought reference life tables and deconvolution models to bear on medfly mortality data gathered from a 3-year study of field-captured individuals that were monitored in the laboratory. The average time-to-death of captured females differed between sampling dates by 23.9, 22.7, and 37.0 days in the 2003, 2004, and 2005 field seasons, respectively. These shifts in average times-to-death provided evidence of changes in population age structure. Estimates indicated that middle-aged medflies (> 30 days) were common in the population. A surprise in the study was the extraordinary longevity observed in field-captured medflies. For example, 19 captured females but no reference females survived in the laboratory for 140 days or more, and 6 captured but no reference males survived in the laboratory for 170 days or more. This paper advances the study of aging in the wild by introducing a new method for estimating age structure in insect populations, demonstrating that major changes in age structure occur in field populations of insects, showing that middle-aged individuals are common in the wild, and revealing the extraordinary lifespans of wild-caught individuals due to their early life experience in the field.
authors: Department of Entomology, University of California, Davis, Davis, CA 95616, USA. jrcarey@ucdavis.edu
authors: James R
authors: JR
authors: Carey
authors: Nikos T
authors: NT
authors: Papadopoulos
authors: Hans-Georg
authors: HG
authors: Müller
authors: Byron I
authors: BI
authors: Katsoyannos
authors: Nikos A
authors: NA
authors: Kouloussis
authors: Jane-Ling
authors: JL
authors: Wang
authors: Kenneth
authors: K
authors: Wachter
authors: Wei
authors: W
authors: Yu
authors: Pablo
authors: P
authors: Liedo
mesh_terms: D000328:Adult; D000375:Aging; D000818:Animals; D033622:Ceratitis capitata / Q000502:physiology*; D015331:Cohort Studies; D003710:Demography; D005260:Female; D006801:Humans; D008017:Life Expectancy; D015993:Life Tables; D008297:Male; D016019:Survival Analysis