E very fall the Inland Northwest is treated to a cloud of fluttery little gray-blue insects. Known as smoky-winged ash aphids, Prociphilus americanus, they are a nuisance, but harmless to humans.
Like many aphids, these insects have a a life history that alternates between two different host plants. For most of the summer these aphids have been living underground, sucking the juice from fir tree roots. During this time, they have multiplied asexually (like a sci-fi movie, individuals occasionally split open to release new daughter aphids)