Thank you for the advice.
I'm amazed also that I have aphids in my sunroom where my lighted shelves are set up--where did they come from? Anyway, I'm going to combine RickCorey's and Woofie's thoughts--giving my seedlings a good spray with water (which usually works with my outside plants when they contract aphids) and then moving them to a more "outside" area which is still somewhat protected from the vagaries of the Cape Cod spring. I'll see if the little green guys disappear, and if not, try a gentle insectidal soap treatment.
I appreciate the help!
