Q: I was piddling around with my hellebores yesterday (Jan 25, 2015) and found a big infestation of aphids under the leaves of my ‘Ivory Prince’. I didn’t know aphids attacked hellebores!
A: You are very observant! Hellebores have their own little insect: hellebore aphid, Macrosiphum hellebori.
Most garden insecticides (click for sources) kill aphids but you have to be precise about getting the product under the leaves, since that’s where they live.