What is the type of interaction in which ants protect aphids in exchange for honeydew?
Ants tending aphids illustrate defensive mutualism. Aphids ingest phloem sap and excrete excess carbohydrate as honeydew, which provides ants with an energy-rich food. Ant workers patrol the colony and attack ladybirds, lacewings, and parasitoid wasps, thereby lowering aphid mortality. Some ants also move aphids to suitable shoots or shelter them during unfavorable conditions. The aphid’s principal service is a resource, whereas the ant’s principal service is defense, so the association is classified by the protective function emphasized. It is not commensalism because both partners can benefi
Ref: Ecology: From Individuals to Ecosystems, Begon et al., 5th Ed., Ch. 8-13
