Abstract:
Climate change affects the rate of insect invasions as well as the abundance, distribution and impacts of such
invasions on a global scale. Among the principal analytical approaches to predicting and understanding
future impacts of biological invasions are Species Distribution Models (SDMs), typically in the form of
correlative Ecological Niche Models (ENMs). An underlying assumption of ENMs is that speciesenvironment
relationships remain preserved during extrapolations in space and time, although this is widely
criticised. The semi-mechanistic modelling platform, CLIMEX, employs a top-down approach using species
ecophysiological traits and is able to avoid some of the issues of extrapolation, making it highly applicable to
investigating biological invasions in the context of climate change. The tephritid fruit flies (Diptera:
Tephritidae) comprise some of the most successful invasive species and serious economic pests around the
world. Here we project 12 tephritid species CLIMEX models into future climate scenarios to examine overall
patterns of climate suitability and forecast potential distributional changes for this group. We further compare
the aggregate response of the group against species-specific responses. We then consider additional drivers
of biological invasions to examine how invasion potential is influenced by climate, fruit production and trade
indices. Considering the group of tephritid species examined here, climate change is predicted to decrease
global climate suitability and to shift the cumulative distribution poleward. However, when examining
species-level patterns, the predominant directionality of range shifts for 11 of the 12 species is eastward.
Most notably, management will need to consider regional changes in fruit fly species invasion potential
where high fruit production, trade indices and predicted distributions of these flies overlap.
