black aphids?

Is there such a critter as a black aphid. My rhubarb was decimated late in the season by something that looked like an aphid but was black. Even though everything I've read says that rhubarb is toxic to aphids and just about every other thing that flies. Now I see the same thing on my sedums. It leaves a great black dusty looking residue on the leaves as though shingle dust had come off in a great storm. There are little black things up and down the stems the way the red and green aphids look. And the sedum and the rhubarb are separated by 20 miles or so. The former being at the horse barns and the sedum at my home. I have not seen this before; any ideas as to its id or treatment.

At this time of year outside, I would just hose them off. I have had black aphids before. They are disgusting.

There are black aphids on my gingers outside...to give you an idea how temperate our climate is at the moment! They don't bother me...........wash em off with the hose sprayer! Elaine

If you want to use more than water, insecticidal soap is a common remedy for aphids, if not the Safer's or some brand name, I sometimes use Mrs. Murphy's Oil Soap.