I put a couple of the "mummies" in a jar to see what emerged. Yesterday I found that one had chewed its way out. It was indeed a small parasitic wasp.
The top image shows the exit hole that the wasp made to get out. In this picture you can also see the "glue" that the larva had used to attach the aphid to the leaf.
The second shot is of the tiny wasp that emerged. (I calculated that the head is only about .03" wide). Had all sorts of complications trying to photograph the wasp last night... hopefully I've sorted things out and will get some better shots today, but this gives you an idea of what was inside.

