Parameter estimation for a descriptive epizootiological model of the infection of a cereal aphid population by a fungal pathogen (entomophthorale)

A descriptive epizootiological model is proposed and parameterized to predict the dynamics of the host-pathogen system “Cereal aphid — entomophthoralean fungusErynia neoaphidis”. The model partitions the host population into distinct classes corresponding to fungal development stages. The dynamics of each class density are described by a set of non-linear ordinary differential equations with the reciprocal of estimated parameter giving average transit or developmental times. The model is compared to the biological data. The experiment was performed under controlled conditions of 20°C and RH >95% using the cereal aphidSitobion avenae as the host. The stability of the model was examined and indicated periodic oscillations, i.e. epizootic intervals separated by longer enzootic periods. In addition, Lotka-Volterra mass action assumption for transmission rate was tested using the data.