Cohabitation inquiline-host in termite nests: does it involve distinct mechanisms?

Nests of the termite Constrictotermes sp. can be cohabited by obligatory inquilines Inquilinitermes sp. Recent studies have shown that inquilines establish themselves in mature nests, possibly during the nidification transition phase of the colony (e.g., from the epigeal to the arboreal habit). It is believed that cohabitation is maintained through spatial segregation of the cohabitants since the inquilines aggregate in the central nest region. Here, we described the cohabitation between Inquilinitermes microceus (Silvestri) and a Constrictotermes species in Sergipe, Northeast Brazil. We compared the cohabitation observed in distinct regions considering hypotheses related to the entry and maintenance of the inquiline in the nests. All Constrictotermes sp. nests found in this region are epigeal, unlike already reported in other studies. Approximately 45% of the nests analyzed were associated with I. microcerus, and cohabitation seemed to be dependent on nest size. The entrance of the inquiline was not related to changes in the nidification habit from soil to trees, as suggested in other studies. In addition, inquilines were not associated with and segregated into the dark walls in the central part of the nest. The cohabitation observed here could involve mechanisms which are distinct from the mechanisms reported in other regions.