Our policy towards pesticides allows invertebrates to thrive around the Gibraltar Botanic Gardens. As is to be expected, a large number of beetle species inhabit the Gibraltar Botanic Gardens. Notable among these are perhaps the large darkling beetles (Tenebrionidae) that thrive on the gardens’ sandy substrate, most notably Akis acuminata. The large ground beetle Scarites buparius (Carabidae) preys on this and other large invertebrates. Other predators include the fearsome-looking Scolopendra cingulatus, Europe’s largest centipede. However, the Gibraltar Botanic Gardens are particularly noteworthy for their density of the Gibraltar Funnelweb Macrothele calpeiana, a large, black spider that is restricted to southern Iberia.
Although they are often seen as enemies of gardens, the Alameda holds a rich and valued assemblage of land molluscs (snails and slugs). Of more obvious benefit to the gardens are the many ladybirds and hoverflies that help to control plant pests such as aphids. Twenty-nine species of ant inhabit a wide variety of habitats in the gardens and, together with earth worms, some of these play a very important role in turning over soil.