Effects of ant dominance on ant-treehopper mutualistic networks in the lowland Colombian rainforest

Arboreal ants are crucial to the ecology of lowland tropical forests, as they rely on sugary liquids from plants and sap-feeding insects to maintain their abundance. Dominant ant species tend to monopolize extra-floral nectaries, limiting access for submissive ants. However, little is known about how the ant dominance differences (ant´s dominance hierarchy -ADH) affect ant-hemiptera mutualistic networks. We searched for treehoppers (Hemiptera: Membracidae and Aetalionidae) and their mutualistic ants in two tropical humid forests in Colombia in 2022 (Magdalena Valley and the Amazon), and recorded species, number of individuals, developmental stages, maternal care behaviors, and tending ants. ADH was assessed by installing baits, and mutualistic networks were reconstructed based on the frequency of interactions between ants and treehoppers. Mutualistic network properties were estimated for both sites, and ADH ranking was correlated with mutualistic network properties. We found 92 and 93 species of treehoppers in Remedios and Leticia, and 30 species of mutualistic ants on each site, with 10 species of ants controlling most interactions. There was no correlation between the dominance of the ant species in the baits and the species that dominated the interactions with treehoppers. Despite differences in composition in the communities of treehoppers and ants at both sites, the properties of the mutualistic networks were similar between both sites. These results demonstrate 1) that different communities show a common pattern in the formation of these interactions, 2) the importance of ants in treehopper communities, and 3) the utility of network reconstructions for the study of mutualisms.