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

distribution of Qfly. For example, it has been reported that Qfly pupae do not survive in the winter months in Melbourne and near Sydney [60], and adults fail to emerge later than mid- April [61]. Further, many subtropical sites in Queensland are marginal in winter for Qfly breeding and general activity [8, 61]. As such, slight temperature increases associated with cli- mate change are projected to substantially elevate the threat that this species poses to horticul- tural industries [62]. For instance, using data from the late 1990s, it was estimated that annual control costs for apple growers around Adelaide may increase by between $346,000 and $1.3 million with a 0.5–2˚C increase in temperature [62]. With the exception of Western Australia, all Australian states and territories are currently free from Medfly, with market access protocols inhibiting movement into other states [21], and incursions met with immediate eradication programs [13]. Our model of baseline habitat indicates suitable conditions for Medfly around most of Australia’s coastal regions. In addition to identifying suitability in the subtropical coastal fringe of Queensland, our model suggested that much of the low-altitude regions in the south-east, including parts of Tasmania, are also Fig 1. Hotspot maps of habitat suitability for the 11 fruit fly species under climate change, when novel environments are included. Hotspot maps of baseline (1960–1990) and future habitat suitability for 11 fruit flies. Suitability was modelled with Maxent, and

thresholded using the 10th percentile of suitability at training presence localities. These maps include projections under novel environments (see S1 File for individual species maps with novel environments included). Colours indicate the number of species for which habitat is projected to be suitable under the majority (� 4) future climate scenarios. Figure was created in R version 3.3.3 [57] (https://www.R-project.org/). https://doi.org/10.1371/journal.pone.0213820.g001 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 11 / 19