The occurrence records of Solenopsis invicta

We initially built a robust database of occurrence data for S. invicta, covering its native range (South America) and invaded range (North America). Occurrence records of S. invicta were obtained from Global Biodiversity Information Facility (GBIF; https://www.gbif.org/), AntWeb (https://www.antweb.org/) and AntMap (https://antmaps.org/). We also incorporated distribution records of S. invicta provided by Wetterer (2013) into the dataset. To minimize spatial sampling bias, we used the nearest neighbor distance (NND) method to thin the data, where occurrence points that were less than 1 km from each other were removed. In parallel, we noted that there were still some distribution records of S. invicta in regions north of 40° North Latitude, although S. invicta is considered a tropical insect. We consulted online distribution records of S. invicta at the Centre for Agriculture and Biosciences International (CABI; https://www.cabidigitallibrary.org/doi/10.1079/cabicompendium.50569), and National Invasive Species Information Center (NISIC; https://www.invasivespeciesinfo.gov/terrestrial/invertebrates/red-imported-fire-ant), but no clear information could be found to support the accuracy of the distribution records at these high latitudes. We thus removed these records to avoid interference caused by the temporary, seasonal distribution and possible erroneous records. Therefore, a total of 6,122 records (421 and 5,701 for the native and invaded ranges, respectively) were retained.