THE XERCES SOCIETY FOR INVERTEBRATE CONSERVATION

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

Hydrometridae are called water measurers or marsh treaders because they walk very carefully and slowly along the water's surface, particularly in marshes and bogs with emergent vegetation. There is only a single genus in North America, Hydrometra.

The marsh treaders have very long prominent antennae that are separated from the eyes by a long snout. Their front legs have apical claws. Their body is stick-like and delicate, with an elongated head and very thin legs.