Agradecimentos: We thank two anonymous referees for valuable comments in the manuscript; R. Constantino and I. Leal for termite and ant identification; G. A. F. Medina for language editing and comments on the manuscript; and students of the under- comments on the manuscript; and students of the under students of the undergraduate course of Biological Sciences in the of Universidade Federal de Mato Grosso do Sul (UFMS) for helping with sampling. This study was conducted during the Ecology Field course fully supported by the Graduate Program in Ecology and Conservation (UFMS). A. C. O. Neves was granted Con- A. C. O. Neves was granted CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQ (CNPq) and Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE MINAS GERAIS - FAPEMIG (Capes/Fapemig) for scholarships Ver menos

Individuals of Cecropia pachystachya Trécul (Urticaceae) host Azteca (Hymenoptera: Formicidae) colonies in their hollow internodes and feed them with glycogen bodies produced in modified petiole bases (trichilia). In turn, ants keep trees free from herbivores and lianas. Here, we report for the first time the association of nests of Nasutitermes ephratae Rambur (Isoptera: Termitidae) with these trees, in South-Pantanal (Brazil). We aimed to describe the Cecropia-ant-termite relationship and to investigate how their coexistence is made possible. We hypothesize that: 1) The frequency of termite nests in C. pachystachya is lower than in neighbor trees; 2) Termite nests occur in trees with lower density of foraging ants; 3) The time that ants take to find and remove live termite baits in C. pachystachya trees is lower in leaves (close to trichilia) than in trunks; 4) Termite nests are fixed preferentially in the smallest and less branched trees; and 5) Termite nests are fixed preferentially distant from the canopies. Unexpectedly, termitaria occurred in C. pachystachya at the same frequency as in other tree species; there was no relationship between ant patrol activity and the occurrence of termite nests in C. pachystachya; and they occurred mainly in the tallest and more branched trees. However, termite nests generally were fixed in the trunk, fork or basal branches, where there is better physical support and ant patrol is more modest. The segregation of termite and ant life-areas may represent a escape strategy of termites in relation to ants inhabiting C. pachystachya, specially during nest establishment. The isolation of termites in fibrous nests and galleries may complete their defense strategy Ver menos