It's only barely visible in one of my pictures, but I confirmed under the microscope that this one has a
prosternal horn and the antennae are mid-way between the eyes and front of the head capsule.
I'm calling this one
Pycnopsyche, but it's a bit perplexing. It seems to key definitively to at least
Couplet 8 of the
Key to Genera of Limnephilidae Larvae. That narrows it down to three genera, and the case seems wrong for the other two. The case looks right for
Pycnopsyche, and it fits one of the key characteristics: "
Abdominal sternum II without
chloride epithelium and
abdominal segment IX with only single
seta on each side of
dorsal sclerite." However, the characteristic "
metanotal sa1 sclerites not fused, although often contiguous" does not seem to fit well. Those
sclerites sure look fused to me, although I can make out a thin groove in the touching halves in the
anterior half under the microscope. Perhaps this is a regional variation.
The only species of
Pycnopsyche documented in Washington state is
Pycnopsyche guttifera, and the colors and markings around the head of this specimen seem to match very well
a specimen of that species from Massachusetts on Bugguide. So I am placing it in that species for now.
Whatever species this is, I photographed
another specimen of seemingly the same species from the same spot a couple months later.