The Facet of Human Impact: Solenopsis invicta Buren, 1972 Spreading around the Atlantic Forest

Abstract

The present investigation deals with some aspects of the diversity of fire ants (Hymenoptera: Formicidae) in their native range. The Red Imported Fire Ant Solenopsis invicta is native to the tropical and subtropical inland territories of South America. In Brazil, it mainly occurs around the Pantanal region and across the Paraguay river, a region composed of grasslands which are seasonally flooded. Recent studies have evidenced this fire ant species is gradually spreading to other regions of Brazil. In the present investigation, we surveyed the molecular diversity of S. invicta populations across fragments of Atlantic Forest in São Paulo, Brazil, using mtDNA COI haplotypes. Fire ant nests were sampled along the highways lining the northern and southern slope sides of the mountain range Serra do Mar, SP, Brazil. Four haplotypes were identified (H1–H4), which were assessed for similarity to deposited records by other authors, revealing that the haplotypes H1 and H2 are likely of foreign origin through recent reintroduction via a marine port to the south of the Serra do Mar mountain range. On the other hand, the haplotypes H3 and H4, predominating among the inland samples from the northern side of the mountain range, were most similar to previous records from more central regions of Brazil. Haplotypes clustered into distinct supergroups, further pointing to the occurrence of two separate expansion waves of S. invicta in the region. We suggest the obtained pattern indicates the mountain range may function as a geographical barrier deferring gene flow.

Preserving a Legacy: Ensuring the Access and Conservation of the Harold (Harry) G. Fowler (1950–2018) Ant Collection and Data

“…Solenopsis invicta is native to South America and is largely distributed in the Pantanal region, at the headwaters of the Paraguay River, an area composed of savannas and seasonally flooded wetlands; its distribution ranges from Porto Velho (Rondônia, north Brazil) to the extreme south of the country (Pitts et al 2018). But its occurrence has been extending to regions of the Brazilian coast into areas of the Atlantic Domain through introductions by anthropogenic means, with the expansion being discussed as a result of a bottleneck effect (Nagatani et al 2022;Ramalho et al 2023). The species has gained worldwide recognition for its remarkable success as an invasive ant in southern United States, Asia and even Europe, earning its place among the top 100 most harmful invasive species globally, according to the IUCN/SSC Invasive Species Specialist Group.…”