Meeting Abstract
Eciton burchellii army ants prey on a wide variety of arthropod taxa, but display avoidance behavior in response to Nasutitermes termites. This study investigates the roles of olfactory signals, termite caste, and active employment of termite defenses in provoking this avoidance behavior. Ants were found to be less likely to bite cotton swabs rubbed into termites than swabs that had been rubbed into a prey species or left clean, indicating that the presence of termite chemicals decrease attack behavior in the ants. This result did not depend on termite caste. Field experiments with the introduction of termites to trails of foraging ants explored the role of termite defensive behavior in repelling ants. Ants were less likely to make physical contact with live soldier termites placed in their trail than they were with a piece of rice, but this decreased likelihood of contact was not seen when the introduced termites had been first killed by freezing. Introduction of live or dead termites both increased the likelihood that ants would divert their direction of motion, but direction-changes of greater magnitude were observed for the live termite treatments. These results suggest that chemicals present on the termites act as olfactory cues to trigger avoidance behavior in the ants, and that defensive behavior by the termites also contributes to repelling the ants.
