shephards and their flock

herds of aphids, which means the ants are aphidherds? the aphids suck the plant juices and excrete a sugary substance called honeydew that the ants eat. The ants protect their herd from predators (ladybird beetles) and move them around.

This species was formally described only 5 or 6 years ago: Aphis echinaceae was seen for years beforehand, but it was never keyed out until recently, when they sent it off to experts for ID, who found it to be a new species.