I'm sure there is something already posted about this, but don't know what exactly to look for. So here's the deal: the other day I found lots of aphids and tiny green worms together on the back of a young but pretty tough helebore leaf. The worms are the same you'd find on your roses, but usually one or two at a time. In this case there were over a dozen on one or two leaves. Were they eating the aphids, the aphids attracting them, or just coincidence? Funny thing: the leaves were not notched or "lacy". I killed all the worms, knocked off the aphids, and now wonder if I had it all backwards...

Ideas?