Modelling insect diseases as functional predators

Many larval diseases of insects allow no recovery once infected. Furthermore, infected individuals are not able to develop into adults and will not therefore reproduce. A simple modelling approach emphasizes the fact that, accordingly, the agents that cause these diseases are functionally predators. It is important to make this distinction and to be cautious in applying inference drawn from models of parasites to these diseases. Sublethal effects are well known in these insect larval diseases, and models show that they have important dynamical implications. Sublethal effects have received less attention in predator–prey interactions, but their functional relationship with insect diseases emphasizes that nonmortality effects of predators may have correspondingly important dynamical implications.