THE XERCES SOCIETY FOR INVERTEBRATE CONSERVATION

Aquatic Invertebrates in Pacific Northwest Freshwater Wetlands
An Identification Guide and Educational Resource

Ephoron is the only genus of Polymitarcyidae that lives in the Northwest, and it is more common in the southeastern parts of the region. It tends to be found in silt or silt/gravel bottoms of streams, rivers, and lakes.

The larvae may be confused with the Ephemeridae because both families have long gills with a feather-like fringe. However, in Polymitarcyidae, the tusks at the front of the head don't curve upward when seen from the side and have small spines on the half of the tusk closest to the head.