Effects of limited volatiles release by plants in tritrophic interactions

We introduce a mathematical model to describe the tritrophic interaction between crop, pest and the pest natural enemy where the release of Volatile Organic Compounds (VOCs) by crop is taken into account. The VOCs may be considered as an indirect defence mechanism of the plant as they attract the pest natural enemies toward the attacked plants. The model dynamics is studied through qualitative analysis and numerical simulations. The factors that may enhance pest disappearance are identified. In particular, we show that VOCs may have a beneficial effect on the environment since their release may be able to stabilize the model dynamics. Specifically, for the parameter values that we have explored, this effect can arise only when both the phenomena of VOCs basic plant release and VOCs plant release due to pest attack are present.