THE XERCES SOCIETY FOR INVERTEBRATE CONSERVATION

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

The Calamoceratidae are common in pools and areas of slow current, although there is only one species in the Northwest. They are the only caddisflies whose labrum has a distinct row of hairs across the front. Otherwise, the larvae of the Northwest species may look similar to long-horned caddisflies (Leptoceridae). They lack plates on top of the third thoracic segment, and appear to have a large rectangular plate on top of the second thoracic segment. They also lack the long antennae characteristic of the leptocerids.

The case of the Northwest species is very distinctive, and may be composed of a narrow, round twig hollowed out down the middle, or a broad piece of bark that is bored into. Scientists have even observed them using abandoned cases of other caddisfly larvae. The Calamoceratidae always make openings at both ends of their case and line the hole with silk. They also may put small pieces of rock or debris around the front opening.