Framework for estimating economic benefits of pest management in pastures.

A generic stochastic simulation model, using data from research and expert opinion, has been developed to estimate the impact of pest damage at the farm level. Farmers aim to maximise productivity, but the impact of insect damage on pasture productivity requires the farmer to trade-off the costs of frequent pasture renewal and pest control. This paper describes a pasture renewal and damage model that incorporates information on pasture growth rate, animal intake over time, and a logistic model of insect damage. The model may be parameterised from typical pest research experiments. Using black beetle (Heteronychus arator) as a case study, we demonstrate how farm vulnerability (e.g. peat soils) can double the required rate of pasture renewal compared to non-vulnerable farms. This modelling framework can assist on-farm decisions by determining economic losses due to pest attack, the optimum frequency of pasture renewal, and the benefits from biosecurity and pest control.