Range, genetic diversity and future of the threatened butterfly, Pieris virginiensis

1. Pieris virginiensis, the West Virginia White butterfly, faces severe potential habitat loss and degradation of existing suitable habitat in the near future from climate change and plant invasion. Increasing isolation and local extinction events resulting from deforestation and climate change have a chance to significantly impact the future of this butterfly. 2. We used genetic analysis and spatial modelling techniques to estimate the current spatial and genetic scope of P. virginiensis. 3. We used linear modelling and machine learning to predict the occurrence of P. virginiensis through space and time using occurrence records between 1879 and 2014 and environmental predictors from a world climate dataset. 4. We predicted the future occurrence of P. virginiensis with climate projections for the year 2070. 5. We sequenced the cytochrome oxidase I, and the internal transcribed spacer region I, in the mitrochondrial and nuclear genomes, respectively, then used a combination of genetic diversity measures and phylogeny construction to evaluate the genetic diversity of P. virginiensis. 6. We found that latitude accounts for nearly one-fifth of the variation in emergence date. 7. Spatial models predicted that P. virginiensis may lose up to 60% of available habitat in the next 50 years. 8. Genetic data indicated some isolation in an Ohio population's COI gene, and low genetic diversity across the range of P. virginiensis in ITS. These may be indicative of either the last glacial expansion or a more recent disturbance. 9. A large effective population size indicates that P. virginiensis are not yet nearing extinction.