Aphids are highly successful insects that feed on the juices of plants. In the summer months they reproduce parthenogenetically at astonishing rates (the young are born pregnant) so that a single female can completely cover a plant source with her offspring and their multitudes of descendants in a matter of days.
Despite their awesome ability to buckle down and take advantage of resources, aphids are almost defenseless and painfully slow-to-react, making them a favorite food of predators like ladybird beetles.
In order to defend themselves, aphids make themselves attractive to allies. They secrete honeydew, a sweet liquid that ants love to consume. The ants, fierce warriors, then protect the aphids from marauding predators, like shepherds protecting their flocks of sheep.
The akamegashiwa (Mallotus japonicus) is an extremely successful pioneering plant (it is often the first to start growing in an empty lot) with paradoxically almost no natural defenses (no spines, poisons or thick bark) -- a somewhat silly state of affairs if one is the only plant on a piece of ground.
The akamegashiwa succeeds in protecting itself in the same way aphids do: it excretes a very sweet liquid from a pair of red eye-shaped structures (akame) found at the base of every leaf. Ants consume the sweet liquid and, in return, protect the plant from insect browsers.
All metaphoric interpretations elucidating why I would post this information on a Japanese politics and society blog gratefully accepted.
Base of an akamegashiwa leaf with ants feeding
Minato-ku, Tokyo Metropolitan District
June 25, 2008
Photo courtesy : MTC