First record of the argentine ant, Linepithema humile (Mayr, 1868), in the Tuscan Archipelago (Italy)

We present the first record of the invasive ant Linepithema humile (Mayr, 1868) in the Tuscan Archipelago. Due to its importance as a conservation area in the Mediterranean basin, the archipelago is now protected as a national park (Parco Nazionale dell’Arcipelago Toscano-PNAT). L. humile colonies were found on three of the seven islands studied: Elba, Giglio and Giannutri. The last two islands host abundant populations, whereas the distribution on Elba, although it is probably underestimated, is sparse and spatially localised. No evidence of presence was found on Montecristo, Gorgona, Pianosa and Capraia. Notably, these are islands where public access is more difficult and restricted. Since this ant has a strong impact on native species, strategic plans for future control are crucial to minimise its effect on the already colonised islands and prevent its spread to the other islands.