I live in Ottawa, and I have a Purple Magnolia Susan that was given to me. As I live in an apartment building it is currently potted. This summer it thrived on the balcony, and when the fall weather came into season, the leaves fell. I brought the tree indoors and it is kept in a moderately lit corner of the den. Three weeks ago it started budding leaves and began looking healthy and happy. Yesterday I discovered small 'worm-like' creatures on the surface of the soil. Currently, I have sealed the soil surface with plastic. What could they be and what should I do. Could I loose the tree?
Probably these. http://ohioline.osu.edu/hyg-fact/2000/2114.html However, your shrub's biggest problem is that you are growing it as a houseplant. This will not work, it needs to be in an intermediate area for the winter, more sheltered than the balcony but not as warm and summerlike as the heated apartment rooms. If you can't move it up to a large tub that doesn't freeze too badly in winter--perhaps with insulation attached to the outside and pulled back in next to the building, in a corner--maybe you will have to get somebody with a sunporch, garage or cold greenhouse to store it for you. Take the plastic off also, roots need to breathe.