Fig. 1

Distribution map of S. invicta and S. richteri across North and South America with marked sampling sites. S. invicta was sampled in three sites in its native range (Her, Ale, Elr) and in two sites in the introduced range (OgGA, PMS). S. richteri was sampled in two sites in its native range (BAA, LfL) and in two sites in the introduced range (BTN, FlNT). The area marked in purple shows the hybridization zone between S. invicta and S. richteri. Distribution is based on [13, 60,61,62,63] and https://www.aphis.usda.gov/plant_health/plant_pest_info/fireants/downloads/fireant.pdf. Sampled populations are: Herr - Herradura, Elr – El Recreo, Ale – Alejandra, PMS - Pascagoula, Mississippi, OgGA - Oglethorpe Co., Georgia, BAA - Buenos Aires, LfL - Las Flores, BTN - Benton Co., Tennessee FlTN - Flatwood, Tennessee