Mate pairing between two drywood termite species with distinct nest site requirements

Nests of social insects are remarkably diverse and often selected to provide species-specific microenvironment suitable to all colony members. In some termites, the nests are permanent structures (= one-piece) selected only once by a founding pair of reproductives during colony establishment. Despite its importance, little is known about how termite reproductive pairs reach a consensus on where to establish a nest. Here we study the interspecific interactions of two Cryptotermes species which have distinct nest-site requirements. Due to global trade, the native C. cavifrons, which is restricted to only dead wood in forest habitats, now encounters the invasive C. brevis, which is found exclusively in human structures in Florida. We examined the potential for interspecific pairing of these two species. Light-trapping confirmed that the reproductives of both species can encounter each other in field conditions, dispersing simultaneously and landing in the same place. They readily engage in heterospecific tandem pairing and maintained movement coordination while searching for a nest site. Furthermore, heterospecific pairs were capable of establishing nest sites together with similar success as conspecific pairs. Notably, same-sex male pairs of C. cavifrons failed to establish nests, suggesting that males may accept heterospecific females as suitable mates. These findings indicate that heterospecific nesting is possible even with the different colony requirements for nest sites. Ongoing work aims to determine the long-term fate of heterospecific pairing and the apparent lack of hybridization between the two species. Understanding these dynamics provides insight into how species boundaries may be maintained in social insects.