A food chain ecoepidemic model: Infection at the bottom trophic level

• First paper to our knowledge on epidemics in food chains.
• Bistability discovered among some equilibria.
• First paper to our knowledge to compute a separatrix surface.
• Used a reliable approximation algorithm for the separatrix.
• Richer dynamics than the corresponding demographic model.

In this paper we consider a three level food web subject to a disease affecting the bottom prey. The resulting dynamics is much richer with respect to the purely demographic model, in that it contains more transcritical bifurcations, gluing together the various equilibria, as well as persistent limit cycles, which are shown to be absent in the classical case. Finally, bistability is discovered among some equilibria, leading to situations in which the computation of their basins of attraction is relevant for the system outcome in terms of its biological implications.