Impacts of climate change on high priority fruit fly species in Australia

suitability (S1 File). Annual mean temperature (33.06%) and mean temperature of the coldest month (32.42%) had the highest contributions to the model for this species (S1 File). The geographic extent of suitable habitat varies across the six climate scenarios. As the cen- tury progresses, gains in new habitat may exceed losses under some scenarios (e.g. see ACCESS1.0, MIROC5 and NorESM1-M; S1 File), while substantial declines occur under oth- ers (e.g. GFDL-ESM2M S1 File), mostly due to contractions in the south and east. Areas of consensus occur along the coastline, although less confidence can be placed in these projec- tions for the Northern Territory and northern Western Australia due to model extrapolation (S1 File). Key regions for host crops in the Top End of Northern Territory, eastern Australia from Cape York to NSW, Victoria, and some parts of Tasmania, may remain suitable for B. tryoni until at least 2070. Major host-plant growing regions in South Australia may also remain suit- able for this species until 2070 (S1 File). Ceratitis capitata. Our model suggests that suitable habitat for C. capitata for the baseline occurred throughout Western Australia, the Northern Territory, the east coast of Queensland to NSW and South Australia (S1 File). We note that scattered records within inland regions of Western Australia are projected as having had low suitability. Annual mean temperature (47.2%) and mean temperature of the coldest month (46.2%) contributed most to the model for this species (S1 File).

Under the future climate scenarios, the geographic extent of suitable habitat is projected to increase and expand inland (S1 File) with much of Victoria and Tasmania likely to be suitable. There is considerable consensus in the distribution of suitable habitat, although consensus declines in New South Wales as the time horizon increases (S1 File). As with other species, MESS maps indicate extrapolation across the northern regions under scenarios from 2050 onwards (S1 File). However, there is high consensus in suitability across the major host plant regions in Queensland, Victoria, and Western Australia. Zeugodacus cucumis. For the baseline period, suitable habitat for Z. cucumis is projected along the northern region of Western Australia and the Northern Territory, north-east Queensland, and south along the east coast to NSW (S1 File). Precipitation of the driest quar- ter (54.3%) and mean temperature of the coldest quarter (36.2%) had the highest permutation importance in the model for this species (S1 File). Under future climate scenarios, the geographic extent of suitable habitat may increase, expanding southward and inland, with most areas that are currently suitable projected to remain so until at least 2070 (S1 File). There is considerable variation among projections for inland regions, likely due to differences in precipitation patterns, indicating higher uncertainty about the future suitability of these regions. There is high consensus in suitability along the east coast, and while consensus is also high in the north MESS maps identify this as a region of

extrapolation. There is little agreement on the suitability of inland regions of New South Wales and Queensland (S1 File). Major commercial growing regions for host crops in Queensland and the Northern Terri- tory are projected to remain climatically suitable for this species until at least 2070 (S1 File). Other major host-plant growing regions in the south and west of the continent will likely remain unsuitable under the time periods considered in this study (S1 File). Future hotspots of pest fruit flies For each time period, we stacked climate suitability maps for all species, to identify regions most likely to contain suitable climate conditions for multiple pest species (i.e. hotspots). As the century progresses, the geographic extent of climatically suitable habitat for most of the 11 Impacts of climate change on high priority fruit fly species in Australia PLOS ONE | https://doi.org/10.1371/journal.pone.0213820 February 13, 2020 9 / 19