I grow
Tropical Milkweed (Asclepias curassavica) and sometimes in mid summer when it's really hot and there's not much air moving, the plants will be covered with aphids and ants. The aphids produce a honeydew that the ants feed on. I love when I see lady bugs/lady beetles in the garden because they devour aphids. I've purchased lady bugs in the past and released them in the garden but unfortunately you can't control where they decide to go. One year as soon as I released them, they flew off to gardens unknown ... I hope my neighbors appreciated my help.
From Wikipedia:
~ Some species of ants "farm" aphids, protecting them on the plants they eat, eating the honeydew the aphids release from the terminations of their alimentary canals. This is a "mutualistic relationship". These "dairying ants" "milk" the aphids by stroking them with their antennae. Some farming ant species gather and store the aphid eggs in their nests over the winter. In the spring, the ants carry the newly hatched aphids back to the plants. Some species of dairying ants (such as the European yellow meadow ant, Lasius flavus) manage large "herds" of aphids that feed on roots of plants in the ant colony. Queens leaving to start a new colony take an aphid egg to found a new herd of underground aphids in the new colony. These farming ants protect the aphids by fighting off aphid predators. ~
From last August ... Aphids!:
