Ant diversity in eucalypt woodland at Koah, the ecotone between Wet Tropics rainforests and the savannah woodlands of the Einasleigh Uplands bioregion

Ants were surveyed on a 12.8 ha bush property at 33 Mile Creek, Koah, in Far North Queensland, that comprised eucalypt woodland and a small disturbed area. Pitfall trapping was conducted at eight sites in 2019 and the same sites again in 2020. Ants were also surveyed incidentally by hand collection throughout the property from 2018 to 2021. We recorded 102 species from 30 genera, of which 53 species were trapped in pitfalls. A further 49 species were recorded only incidentally, greatly enhancing the overall survey and accounting for total richness which was similar to that of other studies in the region notwithstanding their greater range of environmental variation. Ant species composition showed little correspondence to the limited variation in vegetation structure and composition, but functional guild composition showed more interpretable patterns. This included the prevalence of Dominant Dolichoderinae and Hot-Climate Specialists at an open site and a low frequency of Generalised Myrmicinae in the face of Dominant Dolichoderinae at that site. Opportunists were particularly prevalent at the site whose dry sclerophyll understorey suggests moisture stress. There was also evidence of an inverse relationship between the frequency of Opportunists and Generalised Myrmicinae. The ant fauna comprises predominately Australian endemics of Torresian (tropical) biogeographical origin. At least 41 species are only known from Queensland. Five species are not native to Australia, all of which are widespread tramp ants.