I am in Newfoundland.I have had a snowball tree for 7 years. This year about 20-25% of the leaves are curled and when I uncurl them, there are little blue grey like larvae/eggs. What should I do. Lena
Hello Lena, I would take some of those leaves in to a good nursery or some agency in your area to see if you can have the bug ID'd and determine a control method. If you can join the forums and post a photo you may get a good answer here.
Viburnum opulus sterile are prone to aphids that fit your discription, Trounce, a Safer's product works quite well on most aphids, but since these aphids hide in the curl they create you may have to try something more systemic.