New ant records from La Réunion Island (Hymenoptera, Formicidae)

La Réunion Island (Mascarene Archipelago, south-western Indian Ocean) hosts a largely introduced ant fauna, shaped by historical and ongoing human-mediated introductions. Despite previous inventories, the ant fauna of the Island remains incompletely documented and updated faunistic records are needed to refine species checklists and improve knowledge of regional biodiversity. Documenting new occurrences contributes to a better understanding of species distributions, biogeographic patterns and invasion dynamics on oceanic islands, which are particularly vulnerable to biological invasions.

Following recent fieldwork, we report eight new species for La Réunion Island: Brachymymex australis Forel, 1901; Cardiocondyla obscurior Wheeler, 1929; Monomorium exiguum Forel, 1894; Pheidole parva Mayr, 1865; Solenopsis globularia Smith, 1858; Solenopsis gr. pygmaea, Stigmatomma cf. zwaluwenburgi Williams, 1946; and Strumigenys membranifera Emery, 1869. All are introduced species with varying invasiveness status. This work brings the total number of ants known from La Réunion Island to 62, although the presence and identification of some species cited in literature and databases needs verification. Further collections may uncover additional introduced species in urbanised and anthropogenised habitats and native species specific to La Réunion Island or the Mascarene Islands in natural ecosystems.