The potential global distribution of Drosophila suzukii , including consideration of irrigation and Australian host cropping areas

BACKGROUND: Spotted wing drosophila, Drosophila suzukii (Matsumura), is a major fruit fly pest of cherries and berries across Eurasia and North America, with a restricted distribution in the southern hemisphere. It is currently ranked the third greatest threat to Australia on the National Priority Plant Pest (NPPP) list (2024). Various CLIMEX, MaxEnt and mechanistic models of the potential global distribution of D. suzukii have not included irrigation effects. Here, we model the potential global distribution of D. suzukii using CLIMEX, mapped as a composite of natural rainfall and irrigation. For Australia, we overlay the composite potential distribution with host crops to identify commercial areas at risk. RESULTS: The potential distribution of D. suzukii includes all Australian commercial host growing regions. The global projected range extent changes by 6% when irrigation is included, and mean within-range global cell suitability increases by 5 Ecoclimatic Index points. Globally, the CLIMEX results indicate potential range expansion in South America, sub-Saharan Africa, South East Asia and Oceania. CONCLUSION: We have demonstrated a straightforward assessment of the overlap between host production and the potential distribution of a priority pest. This method can be applied to other NPPPs in Australia as part of a broader modelling framework, or to similar cases in other regions.