Spiny looking black and white (more like clear) insects that appear to be living like aphids, on the underside of leaves. I have found two different sunflowers (Helianthus Anuus) that have these. Ants are present; but I did not witness ants collecting honeydew from the insects. A few small, green aphids are visible. The center of the photo shows some apparent damage to the stalk of the leaf; I suspect this was an egg mass. Comments from bugguide.net indicate that these are in the family Membracidae.