The ants (Hymenoptera: Formicidae) of Saba (Netherlands Antilles)
In 1937, 1949 and 1963 P. Wagenaar Hummelinck collected vertebrates with some co-operators. The ants of these expeditions were selected and stored (in alcohol) in the collection of Naturalis Biodiversity Center Leiden Netherland (RMNH). Collecting was done by handpicking, using a knife, forceps, a beetle-sieve and a fine meshed dip-net (Wagenaar Hummelinck 1970) on 30 sites, where on 17 sites ants were found (fig. 4). Sites are distributed over the whole island and where (re)visited during different years. We sorted the ants by species and the final identification was done by P. Boer. Between 7 and 17 March 2018 P. Boer collected ants on Saba. All routes were covered on foot. In the first place, foraging ants were actively looked for, stones were turned, vegetation was scraped off, litter was blown out, plants and trees were searched and tube traps (fig. 3) with attractants were used. These tube traps were filled with liqueur (Leroux Triple Sec Ligueur 15%; Natural Fruit Flavor). The chance to spot ants was not optimal, since it had hardly rained after hurricane Irma (September 2017). It was therefore very dry, which meant that certain species of ants sheltered deep into the earth and thus hide from sight. In addition, many trees had fallen during the recent hurricane, which hindered access here and there and caused local damage to nature. We know for sure that a number of species were not found, which had to be present on Saba.