Interspecific Agonism and Foraging Competition Between Coptotermes formosanus and Coptotermes gestroi (Blattodea: Rhinotermitidae)

We investigated interactions between Coptotermes gestroi (Wasmann) (formerly known as C. vastator) and Coptotermes formosanus Shiraki in forced encounters and in foraging competition. In agonistic assays, termites from each species, with a fixed worker-to-soldier ratio of 9:1, were placed in filter paper-lined petri dishes and allowed to interact over a 24-hour period. Coptotermes gestroi suffered more mortality in all but one interspecific encounter, although only one of these occurrences was statistically significant. There was no significance difference in mortality in any combination of intraspecific, intercolonial pairings within the same species. To investigate foraging competition, termites from colonies of both species were introduced into arenas with a single, centrally located wood food source. Neither species demonstrated an ability to monopolize the food source. There was significant mortality in trials containing both species in comparison to single-species controls; although there was no statistical difference in mortality when the two species were compared with each other.