1. Abdomen dorsoventrally depressed (Fig1.1). Only one species in Ohio. Leucotrichia pictipes
Abdomen laterally compressed (Fig.1.2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Tarsal claws stout and abruptly curved, each with thick, blunt basal seta. . . . . . . . . . . . . . . . 3
Tarsal claws slender, gradually curved, each with thin, pointed basal seta, or seta apparently absent. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Dorsal abdominal setae stout, each arising from small sclerite, dorsal rings distinct; case of 2 long, parallel-sided valvesl of red algae. Only one species in Ohio. Rare, only one specimen collected (Washington Co). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Dibusa angata Ross
Dorsal abdominal setae thin and without basal sclerites, dorsal rings indistinct; 2 eliptical valves of silk case with few or no inclusions; widespread. . . . . . . . . . . . . . . . . . . . . . . Stactobiella*
4. Protibiae each with prominent ventral lobe bearing short, stout setae. . . . . . . . . . . . . . . . . . 5
Protibiae lacking prominent lobes, their setae normal if present. . . . . . . . . . . . . . . . . . . . . . 8
5. Thoracic legs approximately same length. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Middle and hind legs much longer than forelegs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
6. 3 filamentous gills arising from posterior end of abdomen, 1 from dorsomedian position on segment IX, other 2 at lateral sclerites of anal prolegs. . . . . . . . . . . . . . . . . . . . . Hydroptila*
Gills absent from posterior end of abdomen; case portable, laterally compressed, usually consisting of 2 silk valves covered with sand or occasionally filamentous algae, but sometimes dorsoventrally depressed, with dorsal valve carried like tortoise shell and ventral sheet flat; widespread. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ochrotrichia
7. Antennae long and slender, longer than diameter of cluster of stemmata; ventral lobe of each protibia parallel-sided; case protable, compressed, entirely of silk, shaped like flask, open posteriorly; wide spread. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Oxyethira*
Antennae shorter than diameter of cluster of stemmata; ventral lobe of each protibia triangular; case portable, compressed, incorporating filamentous algae in concentric circles; northern. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Agraylea multipuntata Curtis
8. Anal prolegs elongate and cylendrical, projecting prominently beyond general body outline. . 9
Anal prolegs short, conforming to general body outline, not projecting prominently. . . . . . . 10
9. Mesotibiae each with pair of short, stout ventral setae located apically or nearly apically; case protable, made of silk or includind soft mineral material, tapered posteriorly, cylindrical but ususally with longitudinal aor transverse and longitudinal ridges; Rare in Ohio. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Mayatrichia ayama Mosely
Mesotibiae each with pair of ventral setae located about 1/3rd distance from apex; case protable, made with fine sand grains, cylindrical. . . . . . . . . . . . . . . . . . . . . . . . . Neotrichia*
10. Most abdominal segments with prominent, pointed, dorsal and ventral projections; flat silk case open posteriorly, reduced to small circular opening anteriorly. . . . . . Ithytrichia mazon Ross
Abdominal segments without dorsal and ventral projections; silk case with longitudinal ridges. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Orthotrichia*
* OEPA carries these taxa only to level of genus.
Key to Genera of Hydroptilidae Nymphs
