Plant Problems: Aphids

Natural pest control is important to Brooklyn Farm. In the spring we found a outbreak of aphids chomping on the crops. In response we released a platoon of aphid killers: ladybugs. Now that it's autumn we haven't decided what to do. Apparently you can just spray off the plants with a strong stream of water and the aphids won't return to the same spot.
But maybe these aren't even aphids. Does anybody know?