A simulation model of population dynamics of the codling moth, Cydia pomonella

Abstract

A simulation model has been developed that predicts numbers and phenology of a population of codling moth, Cydia pomonella (L.), in an apple orchard. The model is a general insect population model based on the iterative-cohort technique. It operates at two time scales: a fine time scale (one hour) for temperature-dependent physiological processes, and a coarse time scale (one day) for population processes. The population is divided into a specifiable number of stages, and each stage is described by four process functions, which may be of any convenient mathematical form, and may differ among stages. Each stage is divided into cohorts of individuals born or emerged on the same day, and individuals within a cohort are considered probabilistically identical. The model simulates the processes of development, transition among stages, and mortality by using probability distributions representing these processes, and incorporates the effects of pesticides on mortality of the insect. Model output was evaluated by comparison with records of pheromone trap catches of codling moths in commercial apple orchards in North Carolina. The model predicts timing of the first spring flight well, depending on the initial age distribution used. Time between peaks of numbers of adults in the model is about 15 days longer than the observed period between flight peaks in orchards. Sensitivity analysis indicates that this discrepancy may be related to differences between measured ambient temperature and tree canopy temperature. The sensitivities of numbers of insects produced by the model and timing of peaks in numbers present were determined for each of the parameters in the model. The parameters with greatest effect on the model output were those which control the locations of developmental rate functions and survival functions on the temperature scale. In the model, pesticides had a much larger effect on numbers of adults present than records of moths caught in pheromone traps indicate actually occurred, suggesting that moths caught in traps in commercial orchards where effective pesticides are applied may be largely immigrants.

Temperature-dependent development and oviposition models of Riptortus clavatus (Thunberg) (Hemiptera: Alydidae)

“…For female adult development, none of the models mentioned above fit well; therefore, we selected a model from the library of TableCurve (Jandel Scientific, 1996). To describe the relationship between the total fecundity of insects and temperature, several models have been used, such as a square root exponential function (Brown et al, 1978), a quadratic function (Shaffer and Gold, 1985), a linear function (Dover et al, 1979), a Logan (Logan et al, 1976) function (Berry et al, 1991), and an extreme value function (Kim and Lee, 2003). We selected the extreme value function for total fecun-520 H. KIM et al (Kidokoro, 1978;Kono, 1989;Lee et al, 1997;Bae et al, 2005) have studied the effect of temperature on the development of R. clavatus and have used linear models to describe the relationship between temperature and the developmental rate.…”

Life table and population parameters of Lobesia botrana (Den. et Schiff.) under laboratory conditions

“…El estudio del desarrollo de Cydia pomonella L. en laboratorio y a campo, permitió a Rock & Shaffer (1983) determinar el umbral de desarrollo para cumplir las distintas etapas de su ciclo. Shaffer & Gold (1985) desarrollaron un modelo de simulación que predice la fenología de una población de C. pomonella basado en la técnica de cohortes iterativas. Sporleder et al (2004) establecieron un modelo para predecir el tiempo de desarrollo de Phthorimaea operculella Zell., en zonas productoras de papa.…”

PREMISE Insect Model: Integrated Population Dynamics Model for the Ex-ante Evaluation of IPM against Insect Pest

“…Several conditions influence the lifecycle and numbers of generations within a year. The climate, especially the temperature, is a predominant condition that influences insect development and survival [9]. Indeed, in regions with a Mediterranean climate, the numbers of generations and reproductive capacity are much higher compared to Northern Europe.…”

“…In a model that was developed for apple scab (PREMISE apple scab model) [11], the population dynamics are simulated with rather simple arithmetical formulas. Contrary to this scab model, the PREMISE insect model has a solid base with the model components as described by Shaffer and Gold [9]. PREMISE distinguishes six stages for the population dynamics module (Fig.…”

“…[9] as a starting point, a population dynamics module based on iterative-cohort technique has been developed from scratch. This population dynamics module is imperative for the model.…”