Ant predation towards termite and treehopper baits in the Ecuadorian Amazon

AbstractAnimals may develop mutualistic associations with other species, whereby prey offer resources or services in exchange for protection from predators. Alternatively, prey may offer resources or services directly to their would-be predators in exchange for their lives. The latter may be the case of hemipterans that engage in mutualistic interactions with ants by offering a honeydew reward. We test the extent to which a honeydew offering vs. partner recognition may play a role as proximate mechanisms deterring ants from predating upon their hemipteran partners. We show that, when presented with a choice between a hemipteran partner and an alternative prey type, mutualist ants were less likely to attack and more likely to remain probing their hemipteran partners. This occurred even in the absence of an immediate sugary reward, suggesting either an evolved or learned partner recognition response. To a similar extent, however, ants were also less likely to attack the alternative prey type when laced with honey, even after the honey had been depleted, suggesting an ability of ants to recognize new potential sources of honey. Either possibility suggests a degree of innate or learned partner recognition.