Integrated modelling of efficient crop management strategies in response to economic damage potentials of the Western Corn Rootworm in Austria

The spread of the Western Corn Rootworm (WCR; Diabrotica virgifera virgifera) challenges farmers in intensive maize production regions. We model efficient crop management strategies in response to economic damage potentials of the invasive WCR in Austria. A spatially explicit integrated modelling framework has been developed to calculate economic damage potentials from maize yield losses for a past (1975-2005) and a future (2010-2040) period with climate change. The economic damage potentials determine the choice of efficient crop management strategies considering insecticide applications, crop rotations with gradual maize limitations, fertilization intensities and irrigation. The integrated modelling framework includes the crop rotation model CropRota, the bio-physical process model EPIC, and the non-linear land use optimization model BiomAT. Typical crop rotations are simulated by CropRota at the municipality level. They are input to EPIC to simulate crop yields at the 1 km pixel resolution, which are part of the gross margin calculations entering BiomAT. Results of economic damage potentials with a 10% maize yield loss range between 3 €/ha and 180 €/ha, depending on the location, and increase to between 14 €/ha and 903 €/ha at 50% maize yield loss. The analysis of economic damage potentials shows a high regional variability. Moreover, the model results show that a decrease in maize shares combined with moderate fertilization levels is more efficient for WCR control than insecticide use. However, further crop management strategies have to be developed in order to reduce maize yield and economic losses.