Howard is generally correct in giving a value of 0-1 for Moriarty, although some days in the summer with strong lift, the number can go to 2 or 3.

One day a few years ago, I flew through a plume of smoke from a forest fire (at 17,000 ft. MSL) and when I got out of it after about five minutes, the leading edges were about as black as anything I had ever heard about with bugs! It definitely was a 4 or 5 on your scale. It was the first time I ever changed the "Bug" setting on the PNA, and I am glad I did. Took two beers worth of time to clean off the corpses.