A system dynamics model of the population dynamics of Oestrus sp. (Diptera: Oestridae) infesting Iberian ibex, Capra pyrenaica

摘要

We modelled the population biology of Oestrus sp. parasitising the Iberian ibex (Capra pyrenaica), using a system dynamics approach. Levels included in the model were as follows: first-instar larvae, third-instar larvae, pupae and resilient pupae. The values used for flows and auxiliary variables were obtained from the scientific literature, including research on both Oestrus ovis and O. sp.; we assumed that these two species are closely related, both morphologically and from a biological point of view. Simulations provided by our model allowed us to estimate the minimum monthly production of first-instar larvae and thus to establish periodic population dynamics, together with predictions for the number of larval generations. The model predicted 3-4 larval generations per year. The model proved to be very sensitive to minimal changes in a number of variables, especially the first-instar larval production rate. Despite its limitations, this methodology could be a versatile tool for studying the population dynamics of this kind of parasites, and for simulating the effects of control programmes.