The ant assemblages in two common tree species in primary lowland forest of New Guinea were explored using direct canopy access and tuna bait traps. The 19 trees investigated were occupied by 21 ant species of which 18 were canopy inhabitants. On average only 3.6 ant species per tree and 3 species per bait were found. Height of bait position was positively related to ant species richness, with the upper parts of the canopy being occupied by the highest number of species. On the other hand, tree species and study site did not have any effect on ant species richness nor on structure of the ant assemblages. Ant species appeared to be distributed randomly and we did not detect any effect of distance on similarity of ant assemblage occurring on the trees. The dominant species (Crematogaster polita) had certain negative effects on the presence of some species at food sources co-occurring at the same tree, but it did co-occur with the other ants to some extent as well. The majority of species found in the canopy were generalist omnivores (depending mainly on trophobionts or plant exudates).
