The Ant (Hymenoptera: Formicidae) Fauna of Holmes Jungle, a Rainforest Patch in the Seasonal Tropics of Australia's Northern Territory

The ants of Holmes Jungle, a rainforest patch 15 km northeast of Darwin, were surveyed during the 1991/2 wet season using pitfall traps, quadrat counts and direct searches. This is the first comprehensive documentation of any rainforest ant fauna in the Northern Territory. A total of 47 species (six of them introduced) from 24 genera was collected. These include a previously uncollected species ofPolyrhachisFr. Smith, a new generic record (EctomomyrmexMayr) for the Northern Territory, and the first record ofMonomorium talpaEmery from Australia. the most common ants on the ground were Opportunists (particularly species ofParatrechinaMotschoulsky,RhytidoponeraMayr andOdontomachusLatreille), Generalised Myrmicinae (mostlyPheidolespp.), and Cryptic Species (mostlyM. talpa). Canopy ants were abundant and composed almost entirely of tree‐nesting taxa, primarily species ofOecophyllaFr. Smith,CamponotusMayr,PolyrhachisandCrematogasterLund. the majority (68%) of all species have Torresian (tropical) affinities, and 32% can be considered as specialist rainforest taxa. Nearly half (45%) the species also occur in rainforests of the Kimberley region of Western Australia. Species richness and the relative abundances of different functional groups are also similar to those at comparable sites in the Kimberley. However, Holmes Jungle has a considerably greater proportion of Torresian species, a far greater representation of specialist rainforest taxa, and many more arboreal species than occur in Kimberley rainforests.