I was checking out a new stream (new to me) last night and noticed a very odd insect that I had never seen before. I was at Beaver Creek, below Hagerstown MD. The bug was grey blue and looked like it had a little bit of cotton attached to its backside. It looked like a little piece of cotton flying around. Upon closer inspection the cotton was little wisps coming off its back. I took some pictures but I don't think that they were very good (dang thing wouldn't pose or even hold still). The wings were up-write and I didn't notice a definable tail. Is this just a mayfly molting? I have never seen anything like this.