Co-existence of ants and termites in Cecropia pachystachya Trécul (Urticaceae)

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 system and to investigate how their coexistence is made possible. For this we compared the frequency of termitaria between C. pachystachya and another tree species, and the patrol activity of ants between individuals of C. pachystachya with and without termite nests. We verified how long ants took to find and remove live termite baits in C. pachystachya trees and we described the architecture of C. pachystachya individuals with and without termite nests. 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. pachystachia. These results suggest that there is no effect of ant patroling activity on termitaria frequency. However, they occurred mainly in the tallest and more branched individuals, and generally were set in the lower portion of the trees, associated with the trunk, fork or basal branches. There, N. ephratae find the opportunity to establish their nests, because ants remain close to young-active trichilia at the tip of branches, leaving the bottom of the tree almost free of patrol. The physical segregation of termite and ant life-areas may represent a escape strategy of termites in relation to ants inhabiting C. pachystachya.