Communication between ants (Hymenoptera: Formicidae) and aphids (Homoptera: Aphididae).

Abstract

Communication is a signal exchange between organisms that results in a mutually adaptive change in behavior. I investigated whether communication occurs between ant and aphids in ant-tended aphid colonies on a Populus balsamifera L. sapling at UMBS. Individual aphids were monitored to determine the sequence and frequency of behavioral interactions with attending ants. Sequence analysis showed that two-act behavioral transitions were significantly non random. A five-act sequence of discrete interactions (involving honeydew feeding by an ant initiated by the aphid raising its legs and abdomen) occurred in 69.2% of the replicates (n=13). Production rate of honeydew by the aphids significantly decreased when ants were removed (t = 3.707, P = 0.0025, df = 14.3) and aphids were seen to handle honeydew differently in those colonies. These results indicate that signal exchange takes place between the ants and aphids found in these colonies. This exchange results in a change in behavior that is, most likely, beneficial to both organisms.