My greenhouse tomatoes have a few aphids on them. It was bound to happen. They are flying off the drying fields into our lush heaven. I have an organic oil spray and I thought about ordering beneficial insects but then I remembered my bug blaster. (dope slap) It's a spray nozzle that emits a flat-2 dimensional blast of water. Aphids being soft bodied insects can't handle the force of the spray. This tool is very effective for mites too who dislike moisture and congregate on the underside of the leaves where rain won't wash them off.
win-win, plants love it, pests hate it, good for the environment