ETD

• ants
• checklist
• invasive
• parasite
• tuscan archipelago

Ants (Hymenoptera, Formicidae) are ecologically and economically important, yet our full appreciation of them is prevented by several knowledge gaps. One of the most important is the so called 'Wallacean shortfall', i.e. the lack of knowledge about geographical distribution of most species. This particularly applies to specific areas, such as archipelagos. This thesis contributes to the faunistic knowledge of the ants of the Tuscan Archipelago, which represents a poorly studied Mediterranean insular system from a myrmecological perspective, with most existing data based on outdated or fragmentary records from the early-to-mid 20th century. This study provides a comprehensive and taxonomically updated checklist of ant fauna across all seven main islands (Capraia, Elba, Giannutri, Giglio, Gorgona, Montecristo, and Pianosa) through integration of literature review, museum/private collection revision, and new field samplings. A total of 57 ant species belonging to 23 genera and 5 subfamilies were documented of which 23 new species-island association. Giannutri Island received particular focus through intensive sampling using multiple complementary methods (hand samplings, pitfall traps, Winkler extraction, honey traps) over 74 sampling days, yielding 24 confirmed species. Moreover the sampling has allowed to find 6 new species for the island: Aphaenogaster ichnusa, Hypoponera punctatissima, Lasius lasioides, Solenopsis lusitanica, Temnothorax algiricus and Tetramorium semilaeve. Two species of conservation interest were monitored on Giannutri: the rare social parasite Plagiolepis xene, found in three spatial clusters with low parasitism rates, and the invasive Argentine ant Linepithema humile, whose distribution has remained stable since 2016 and confined to areas near human settlements. While the faunistic knowledge of the ant of this area is likely to be incomplete, due to uneven sampling, preliminary community analysis revealed that island area dissimilarity was the only significant predictor of ant community dissimilarity. This baseline assessment addresses critical knowledge gaps in Mediterranean island myrmecology and calls for future systematic monitoring, particularly for species of conservation concern in these valuable but vulnerable insular ecosystems.