DDM-Sim 0.1. A generic software component for time varying delay models with attrition

In population ecology, distributed delay models allow simulating the stochastic development of poikilotherm cohorts and age-structured populations. The theory of time distributed delay models was explained by Manetsch (1976) and successively applied to insect phenologies. Vansickle (1977) extended the time distributed delay models to include 'attrition', intended as the proportional loss during the development processo Gutierrez and Baumgartner (1984) used Vansickle's model to simulate the dynamics of interacting populations. Time distributed delay models are widely used to represent the phenology and the dynamics of poikilothermic populations and applied to integrated crop and pest management. DDM-Sim 0.1 (Distributed Delay Model Simulator) is the first version of a Microsoft .NET 2.0 generic software component for time distributed delay models. DDM-Sim 0.1 has been developed for the framework BioMA being developed at the JRC, but its software architecture allows the easy re-use as a stand-alone component or for the implementation in other modelling framework without the need of recompilation. DDM-Sim 0.1 can be easily parameterized with population specific development parameters (including the number of development stages, mean developmental time and variance for each stage, number of k sub-stages for each stage, overall survival including temperature-dependent intrinsic and extrinsic survival) in order to be adapted to specific cases. It requires daily or hourly temperature data. At the current state of development, DDM-Sim 0.1 allows the simulation of the development of multi-generations of single-species populations with age-structure. Future developments of the component include the extension to simulate plant-herbivore and predatorprey interactions.