First Records and Expanding Distribution of a Small Big-Headed Ant, Pheidole parva, in Florida, USA.

Pheidole parva Mayr (1865) is a small ubiquitous ant native to the Indomalayan region where it is considered a pest in healthcare facilities. This tramp ant was first reported outside its native range more than 100 years ago in the Seychelles Islands. Since then, it has been found in other areas of the Old World, where it was likely accidentally introduced via trading ships. In the 2000s, this ant was detected in Japan (2001), the Arabian Peninsula (2009), and recently in the Mediterranean island of Cyprus (2023) and Lebanon (2025). Here, we describe its first occurrence in North America, in the state of Florida where both Nearctic and Neotropical realms meet. Our findings are based on recent Pheidole parva specimens collected throughout the state, curated iNaturalist observations, Antweb data, and DNA barcoding based on the mitochondrial cytochrome oxidase subunit I (COI) gene. Among the 26 P. parva specimens analyzed from Florida, we found three different COI haplotypes. Two of them were also found in other introduced areas; however, one of the haplotypes has only been detected in a native population. The three haplotypes were distributed throughout the state with no clear geographical structure, consistent with multiple introductions and broad establishment of this non-native ant in Florida.