Help a sister out?

I don't know if anyone reading this is an entomologist-type or a forester or anything, but I have a bug question.

My mom called me this evening (she lives in Central Illinois) asking about some little bugs that have appeared where she lives.

Her first question is: do you know what kind of bug looks like it has quilt batting on it? Which I figured was the set-up for a joke, but it isn't. They're real bugs, small (she said 1/4 inch), sort of blackish under the wool but not, as far as she could determine, beetles (I asked her: beetle or fly? and she couldn't tell me for sure).

I looked up a bit and all I'm turning up are wooly aphids, which seem unlikely for two reasons: first, wooly aphids are darned small (1 mm, which is like, what, 1/32 inch?) and second, although aphids do have alate stages, they spend most of their lives stuck to and sucking on plants.

Her concern is that it's some kind of "bad" bug that will kill plants, or that it's a first wave of a new invasive species for the area. I suggested she catch some and take them to the campus entomologist (which is what *I* would do), but she didn't seem gung ho on that idea. So I said I'd "ask around," except we have no campus entomologist (I'm actually the closest thing and I'm a pretty poor entomologist seeing as I've never actually done coursework in that area, everything I know I picked up by reading or trial and error).