Insect population simulation

Simulation of insect populations using systems dynamics methodology is discussed. The differences between the mathematical processes used to project long-term population regeneration and growth, and the processes used to project short-term within generation growth and development are presented. Both involve projection of a population level at a future time based on present population numbers. A framework is described for using systems dynamics methodology and the GASP IV simulation language to simulate the growth and development of the population of an insect having complete metamorphosis, i.e. staged development. Progression from stage to stage within the life cycle is either related to chronological or to physiological time depending on whether the nutrients for growth are contained within the insect at the beginning of the developmental stage or whether feeding occurs. Progression and mortality are continuous functions of heat energy accumulation in the environment and both are related to physiological age. Both progression and mortality are attenuated by environmental factors such as air temperature, air moisture content, air movement, and rain. An example simulation of a Hessian fly population is presented.