Simulation of predator-prey relationships in an acarine system

Simulation with a computer can be an aid in the analysis of complex ecological processes. When such processes bear upon the behaviour of individual plants or animals, they often depend on chance variables. Such stochastic processes cannot be correctly simulated with a deterministic model, when there are non‐linear relationships between output variables and chance variables. On the other hand, simulation with a stochastic model using a random function generator has to be repeated several times to obtain reliable expectation values of the output variables. A method is described for simulation of stochastic processes in one run, which provides acceptable expectation values. The method is applied in a program for simulation of a predation process, which occurs when the predacious mite, Typhiodromus occidentalis, preys on eggs of the spider mite Tetranychus urticae. The results are compared with those obtained by regular deterministic and stochastic simulation.