Cost-benefit analysis of controlling the spotted wing drosophila (Drosophila suzukii (Matsumura)) spread and infestation of soft fruits in Trentino, Northern Italy

BACKGROUND We assessed the economic impact of the invasive pest Drosophila suzukii (Matsumura) on the soft fruit industry (strawberries, raspberries, blackberries, and blueberries) in Trentino, Northern Italy, using cost-benefit analysis. A conventional integrated pest management (IPM) based on insecticide, mass trapping and cultural measures is compared to an upgraded IPM strategy based on exclusion netting. Costs and benefits associated with the change between the two are estimated in order to evaluate the most profitable strategy from the societal point of view. The robustness of the results to uncertainty in parameters’ values is assessed through probabilistic sensitivity analysis. RESULTS In a period of low pest pressure, the conventional IPM strategy would likely be more profitable than no management. However, with higher pest pressure levels, the upgraded IPM strategy would increasingly be more profitable than the conventional one as pest damage levels increase. CONCLUSION For the problem considered in this study, insecticide-based management is expected to prove less and less profitable, as rising pest pressure levels lead to an intensification of the insecticide applications. Conversely, exclusion netting, despite being more expensive, is expected to be much more profitable, both for its effectiveness in reducing pest pressure and for its lower societal impact.