This specimen resembled several others of around the same size and perhaps the same species, which were pretty common in my February sample from the upper Yakima. Unfortunately, I misplaced the specimen before I could get it under a microscope for a definitive ID.
Litobrancha on Oct 20, 2006October 20th, 2006, 7:59 am EDT
a great thing about cheumatopsyche (which i believe this is) is that the IX segment ventral plates are almost always completely differentiated to the base. hydropsyche medial margins are more indistinct near the base.
also cheumatopsyche almost always lacks F1 in the hind wings, although aberrant specimens are common. the best character is the distance between M and Cu veins in the hind wing, other hydropsychids are parallel and close together, cheumatopsyche diverges a bit.