| 1a. Basal setae reaching to or nearly to end of tarsal claw; mandibles with entire edge. | |
| 1b. Basal setae far short of end of claw; mandibles with 2 or more teeth | |
| 2a. Metanotal sa1 sclerites absent; sa1 setae in a transverse band; CASE strongly tapered(like a cornucopia horn), anterior opening usually oblique with dorsal edge extending beyond ventral edge for final instar. Apatania | |
| 2b. Metanotal sa1 sclerites present, or if absent, sa1 setae not in a transverse band. Allomyia | |
| 3a. Most abdominal gills single. | |
| 3b. Most abdominal gills multiple | |
| 4a. Metanotal sa1 and sa2 sclerites large, distance between sa2 sclerites no more than twice maximum dimension of one sa2 sclerite. CASE Slender straight, scarcely tapered tube case of coarse rocks, often with long plant material attaached. Ecclisomyia | |
| 4b. Metanotal sa1 and sa2 sclerites small, distance between sa2 sclerites more than twice trhe maximum distance of a single sa2 sclerite, sa1 sclerites sometimes fused | |
| 5a. Lateral humps of segment I with one rounded posterior sclerite(sometimes hard to see, look for shiny surface) and one elongate dorsal sclerite at base of lateral hump. CASE Staight tube of rocks and wood fragments. Psychoglypha | |
| 5b. Lateral humps of segment I with only one sclerite. | |
| 6a. Lateral humps of segment I with a large single sclerite enclosing posterior half and extending posterodoraslly as an irregulr lobe. CASE Leaves or bark formed in a flattened tube with lateral seams and a narrow flange along each side. Chyranda centralis | |
| 6b. Lateral humps of segemnt I with one elongate sclerite at the base, half as long as the basal width of the hump. Homophylax | |
| 7a. Most gills with 3 branches, none with more than four. | |
| 7b. At least some gills with more than 4 branches. 13 | |
| 8a. Dorsum of head striped or banded with dark and light colors. Limnephilus externus | |
| 8b. Dorsum of head one uniform color, occasionally with spots or dots at points of muscle attachment | |
| 9a. Femur of metathoracic leg with more than 2 major setae along the ventral edge; plae stripe down center of head, pro and meso thoraxes. | |
| 9b. Femur of metathoracic leg with two major setae along ventral edge. | |
| 10a. Metanotal sa1 sclerites fused. CASE Hollow twig with a ring of bark pieces anteriorly. Amphicosmoecus | |
| 10b. Metanotal sclerites clearly separate. CASE Pieces of wood and bark. Onocosmoecus | |
| 11a. Abdominal tergum VII with median gap in transverse band of setae. CASE Cylindrical case of longitudinally arranged sedge leaves. Grammotaulius | |
| 11b. Abdominal tegum VII with continuous band of setae. | |
| 12a. Chloride epithilia present dorsally, laterally and ventrally on most abdominal segments. CASE Plant, rock, shells, seeds. Asynarchus nigriculus | |
| 12b. Chloride epithelia absent dorsally, maybe present laterally, always present ventrally on most abdominal segments Limnephilus, Philarctus | |
| 13a. Metanotum with all setae confined to primary sclerites. CASE Longitudinally arranged lengths of sedge leaves or of fragments of bark and leaves. Lenarchus | |
| 13b. Metanotum with at least a few setae between primary sclerites (look for broken setae). | |
| 14a. Lateral series of gills single-branched and on segement II only, occaisionally also III. CASE coarse, small rocks. Psychoronia | |
| 14b. Lateral series of gills present on segments II-V, some with more than one branch. CASE small rocks. Hesperophylax |
