Potential global distribution of Aleurocanthus woglumi considering climate change and irrigation

Geiger climate classification system to determine that A. woglumi occurs in climatic zones that also occur in European countries, making them potentially suitable for establishment [30]. A model that relies on the thermal requirements of the insect and global climate change scenarios has been used to forecast changes in the number of generations that might be expected annu- ally in the state of Para´ in Brazil [42]. CLIMEX (Hearne Scientific Software, Melbourne, Australia) is frequently used in applied ecological studies by government agencies and research organisations for a range of applica- tions including pest risk assessment, exploring the potential effects of climate change and sup- porting biological control research [21,43]. CLIMEX is a hybrid inductive-deductive ecological niche model. Using CLIMEX, the factors limiting a species’ range can be inferred from its known geographical distribution, relative abundance or seasonal phenology. Where available, ecophysiological information from experimental domains can help inform the parameterisa- tion of growth indices and factors in CLIMEX such as the base temperature for development and the onset of stresses. CLIMEX is a dynamic model with the ability to incorporate the inter- actions between environmental variables and functions across all latitudes, climate zones and seasons as required for biosecurity and global change applications [44]. Because its stress and growth functions are arranged in accordance with the Law of Tolerance [45,46] and the Law of

the Minimum [47], CLIMEX is relatively immune from the novel climates transferability prob- lems that challenge correlative species distribution models [48,49]. In this study we use CLIMEX to assess the climatic potential for establishment of A. woglumi in new regions, considering the geographical locations where irrigation is practiced. We apply a climate change scenario to highlight emerging areas at risk that should be factored into pest risk analyses and the formulation of biosecurity policies regarding A. woglumi. Materials and methods CLIMEX CLIMEX is used to estimate the potential establishment of species using climate information and produces maps describing the climate suitability for population growth and survival, dis- tinguishing between conditions for establishment or ephemeral occupancy. Here, we used CLIMEX 4.1 (Hearne Scientific Software, Melbourne, Australia) to estimate the global poten- tial distribution of A. woglumi. The CLIMEX “Compare Locations” model uses a meteorologi- cal database consisting of monthly long-term average climatic variables for any number of locations [44]. The current distribution of a species can be used to infer its climate preferences, especially the stresses that mostly limit a species’ range. The Ecoclimatic Index (EI) represents the overall climatic suitability of a region for the modelled species. The Ecoclimatic Index (EI) combines the growth and stress indices. An EI of 0 indicates that the location is not favourable for the long-term survival of the species. A maximum EI value of 100 is only achievable under

stable climatic conditions, usually found in equatorial locations. The Growth Index is derived using a Temperature Index (TI) and a Moisture Index (MI) that describe the modelled species’ response to temperature and moisture conditions and indicates the climate suitability for pop- ulation growth. The weekly Growth Index (GIW) is integrated to give an annual Growth Index (GIA). The stress indices (cold, hot, dry, wet), and occasionally their interactions (hot-dry, cold-dry, hot-wet and cold-wet), represent potential limiting factors that restrict a species’ abil- ity to survive. Stresses largely define a species’ potential geographical distribution, while the growth indices mostly describe the potential for population growth within that range bound- ary [44]. CLIMEX results were exported into GIS software (ArcGIS Pro, Version 2.7.1, Red- lands, CA: Environmental Systems Research Institute, Inc., https://www.esri.com). PLOS ONE Potential global distribution of Aleurocanthus woglumi PLOS ONE | https://doi.org/10.1371/journal.pone.0261626 December 20, 2021 3 / 18