Code from: Source–sink dynamics explains the coexistence of the invasive pest <em>Dryocosmus kuriphilus</em> and its biological control agent <em>Torymus sinensis</em> across French Eastern Pyrenees

This dataset includes the codes we developed to model the spread of a gall-forming hymenopteran parasite of chestnut trees, Dryocosmus kuriphilus, and its control agent, Torymus sinensis, across 23 natural forest sites located in the French Eastern Pyrenees. The model of D. kuriphilus - T. sinensis interactions was derived from the founding host-parasitoid model proposed by Nicholson-Bailey and adapted to account for the effects of the bottom-up and top-down factors regulating the invasion of D. kuriphilus. The first code then corresponds to the modelling of D. kuriphilus and T. sinensis population dynamic within one site, while the second code is an extension of the within-site modelling into a two-site model, allowing for the study of the effects of the pest and control agent dispersal between two sites on their population dynamics.