Sex ratio and dynamic behavior in populations of the exotic blowfly Chrysomya albiceps (Diptera, Calliphoridae).
Sex ratio is an essential component of life history to be considered in population growth. Chrysomya albiceps is a blowfly species with a naturally biased sex ratio. In this study, we evaluated the impact of changes in sex ratio on the dynamic behavior of C. albiceps using a density-dependent mathematical model that incorporated demographic parameters such as survival and fecundity. These parameters were obtained by exponential regression, with survival and fecundity being estimated experimentally as a function of larval density. Bifurcation diagram of the results indicated the evolution of stable equilibrium points as a function of sex ratio. A continually increasing sex ratio yielded a hierarchy of bifurcating stable equilibrium points that evolved into a chaotic regime. The demographic parameters obtained by exponential regression were also changed to maximum and minimum values in order to analyze their influence on dynamic behavior with sex ratio being considered as an independent variable. Bifurcations with periodicity windows between chaos regimes were also found.
Serra
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Departamento de Parasitologia, Instituto de Biociencias, Universidade Estadual Paulista, 18618-000, Botucatu, SP, Brazil.
Godoy
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Von Zuben
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Von Zuben
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Reis
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D000818:Animals; D004175:Diptera / Q000254:growth & development / Q000502:physiology*; D005260:Female; D005298:Fertility / Q000502:physiology; D007814:Larva / Q000502:physiology; D008136:Longevity; D008297:Male; D008954:Models, Biological; D011156:Population Density; D011157:Population Dynamics; D012744:Sex Ratio