Beginner Gardening: What's killing my boxwood shrub?, 1 by ejpontius

ejpontius wrote:
I'm not much of a gardener and don't spend a lot of time in the yard other than mowing the lawn and pulling the occasional weed. So I'm an idiot when it comes to gardening. I noticed today that one of my boxwood shrubs has pretty much died, all but one little area. I thought at first it might have been from a dry summer and a couple of recent freezes. But on closer inspection, I can see the that leaves are covered in little white lines and that it seems to have spread to the shrub next to it. I thought at first they were worms or insects, but they don't move. Then thought it might be some kind of fungus.
I'm not sure what it is or what to do about it. So I could us some help and direction.
I've attached a few photographs of what the leaves look like.

Thanks,

Erik