THE XERCES SOCIETY FOR INVERTEBRATE CONSERVATION

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

Hoodcase maker caddisflies live in the eastern U.S. (west to the Rockies, across southern Canada) and the far north, but are not commonly found in the Northwest. They live on sandy or muddy substrates, mostly in still waters or slower parts of rivers, or in cold springs.

Molannidae larvae are similar to the longhorned case makers (Leptoceridae) in that they lack plates on top of the third thoracic segment and the plates on top of the middle thoracic segment are rather thin. However, they don't have long antennae, and the claws on their back legs are highly modified (either long and thin or short and stubby).

Molannidae larvae build distinctive cases out of fine sand grains and rock fragments. The bases are flattened and have a flange at each side and a "hood" or extension that continues from the top of the case past the front opening. These cases are delicate and the flanges and hood may break off. One of the longhorned case makers (Ceraclea) may build a similar case, but it will nearly seal off the rear opening with silk. In the hoodcase makers, the rear opening of the case is wide and rough.