Not just any tree: the influence of leaf characteristics on the nest site selection ofAsian weaver ants

The connection between plant species and nest site preference for the Asian weaver ant Oecophylla smaragdina remainspoorly understood despite their common occurrence in the urban areas of tropical regions. We predicted that plant species with specificleaf characteristics influence the nesting preference of Asian weaver ants, given that plant foliage is the main component of their neststructure. We studied the leaf characteristics of the tree species in which their nests were detected, including leaf shape, leaf apex shape,and leaf arrangement. Of the 206 total trees among the 20 tree species sampled, 185 trees from 18 tree species had at least one nest.Trees of the genus Lagerstroemia had the highest median nest abundance, whereas all Roystonea regia and Caryota no trees, and someSamanea saman trees, were not occupied by O. smaragdina. For the trees found to have O. smaragdina nests, the nest abundance in eachtree ranged between 1 and 16 nests, with the majority having fewer than 10 nests per tree (4.38 ± 4.45). Based on nest abundance, theoblong and elliptic leaf shapes (LS), the cuspidate leaf apex shape (LX), and the opposite leaf arrangement (LR) were the most used fornest construction, consisting of more than 50% of the total in each respective category. A Kruskal–Wallis test revealed that O. smaragdinanest site preference is influenced by LX and LR but not by LS. Additionally, O. smaragdina nest abundance was negatively correlated toleaf surface ratio but insignificant for leaf surface area. These preferred qualitative and quantitative leaf characteristics determine thespecies of plants used as nesting sites to facilitate nest-building efficiency and the establishment of Asian weaver ant colonies.