I've got a pot of variegated lily-of-the-valley (Convallaria majalis 'Albostriata') in a pot on the north side of my house in East Van. The leaves start to look scrappy after the plant blooms each year. When I turn over the leaves, I see these white bugs, and the leaves are sticky. I suspect that there are several issues here. Is there anything that can be done to bring the plant back to health before the end of the season? Any advice is appreciated.