The model of predator–prey (parasitoid–host) processes developed here is a generalization of single-species processes in which food supply is so depleted that it may take several generations to recover. The model is characterized by several parameters, each representing a certain ecological attribute. I investigate the model’s dynamics by varying the values of these parameters, and by exposing them to exogenous influences.

The above investigation applies to a laboratory experiment in which the predator has no choice but feeds only on the given prey. This would not occur in a natural environment where several predator species feed on several prey species. As a result, we often see an interaction between a complex of predator (parasitoid) species and a complex of prey (host) species. I investigate the dynamics of the complex-vs-complex interactions as open systems (each species may move from one complex to another) to interpret what we observe in natural situations.