An individual-based model of an acarine tritrophic system: lima bean, Phaseolus lunatus L., twospotted spider mite, Tetranychus urticae (Acari: Tetranychidae), and Phytoseiulus persimilis (Acari: Phytoseiidae)

An individual-based simulation (IBS) was constructed that represents the dynamics among a lima bean seedling, twospotted spider mite (TSM), and Phytoseiulus persimilis. The parameters were derived from a combination of experiments and values found in the literature. The reductionist nature of individual-based modeling makes use of highly specific behavioral experiments. The simulation’s complex population dynamics compare well with data taken from validation experiments (adj R2=0.85). The major practical advantage of this technique is the degree of detail that the simulation can predict in population structure. Because IBSs accommodate behavioral complexity, they can make better predictions of the interactions in small populations than simplified analytical models. This reductionism takes questions about population dynamics and reduces them to the experimentally measurable behavioral factors that are important to the emergent population.