Ants Tending Aphids on Camellia Leaves in album plants
In Albums: nature plants broadleaf evergreens ants
Jun 12th, 2011, by Alex Zorach
Humans are not the only species to actively tend or raise other animals as a food source. Here, ants are doing the same: these ants have a symbiotic relationship with the aphids. The aphids dine on plant juices, and exude a honey-like substance, which the ants use as a food source. Ants lack the mouthparts and digestive systems to effectively feed on the plants directly. Ants benefit from a newly available food source, and the aphids benefit from a fast-moving, stronger insect that can carry them from place to place, and protect them from predators.
This relationship is actually more than just mutualism. Note that the leaves in the picture look completely healthy, and indeed, show no evidence of any insect damage: the aphids are living off the plant, but do not kill it. The ants, in protecting the aphids, also protect the plant from other would-be herbivores that would eat the plant (without benefiting the ants). The plant thus benefits as well, creating a system where all three species benefit and work together.
You can also view a broader picture of the whole Camellia plant here.