Male Glossosoma (Little Brown Short-horned Sedge) Caddisfly Adult Pictures

Key characteristics verified under the microscope:
-The head has 3 ocelli.
-Maxillary palp has 5 segments, with the second segment rounded. In some of the pictures it looks like 6 with the 3rd segment rounded, but the basal "segment" in that case isn't part of the palp.
-Foretibiae lack preapical spurs.
-Pronotum with mesal setose warts widely spaced.

All of this very clearly indicates Glossosomatidae. Beyond there:

-The tibial spur counts (fore / middle / hind tibiae) are 2, 4, and 4.
-From the pictures, the hind wing discoidal cell is closed, not open. Subfamily Glossosomatinae.
-The upper and lower parts of the mesepisternum are separated by a constriction, not a transverse suture. Microscope picture included.

This leads to a very confident genus ID of Glossosoma. I don't have the information to take it to species.

This caddisfly was collected from the Cedar River in Washington on July 2nd, 2021 and added to Troutnut.com by Troutnut on July 4th, 2021.

Start a Discussion of Adult