243 

 Denning: Trichoptera 



— Teeth on anal hooks not comblike (fig. 10:5/); larval 

 case not snaillike 12 



12. Labrum much longer than broad; pronotum and meso- 

 notum sclerotized, metanotum with wide anterior plate 

 and a pair of oblong lateral plates (fig. I0:5d) .... 



ODONTOCERIDAE 



— Labrum broader than long; pronotum sclerotized, meso- 

 notum may or may not be sclerotized, metanotum with 

 1 or 2 small round or poorly defined sclerites 13 



13. Anal hooks formed of 2 or 3 long, stout teeth (fig. 

 10:5A); mesonotum with small sclerotized plates .... 

 SERICOSTOMATIDAE 



— Anal hooks formed of a single large tooth with 1 or 

 more small teeth on dorsal edge (fig. 10:5/) 14 



14. Pronotum with deep transverse impression across 

 the sclerite; antennae small, closer to mandibles than 

 to eyes BRACHYCENTRIDAE 



— Pronotum without such a deep transverse impression 

 or with only a slight concave depression across 

 sclerite 15 



15. Tarsal claws of hind legs very long, as long as tibia 

 BERAEIDAE 



— Tarsal claws of hind legs much shorter than tibia. . 16 



16. Mesonotum divided into 2 or 3 pairs of plates and 

 metanotum with 3 or 4 pairs of plates; tracheal gills 

 in groups of 3 or 4 GOERIDAE 



— Mesonotum consisting of a single large sclerite, not 

 divided into several pairs of plates 17 



17. Antennae located close to the eye (fig. 10:5/;); first 

 abdominal segment lacking a dorsal spacing tubercle 



LEPIDOSTOMATIDAE 



— Antennae usually located midway between the eyes 

 and base of the mandibles, if not, then closer to man- 

 dibles than to the eyes (fig. 10:5;'); first abdominal 

 segment with a dorsal tubercle (fig. 10:6) 



LIMNEPHILIDAE 



coxa 

 -trochanter 

 femur 

 •-tibia 

 -■tarsus 

 ~-claw 



Fig. 10:6. Limnephilus submoni lifer, larva and pupa, illustrating 

 terminology of structures (Ross, 1944). 



Family RHYACOP HILIDAE 



About one hundred fifty Nearctic species representing 

 seven genera have been described to date. Six genera 

 and forty-three species have thus far been recorded 

 from California. The free-living larvae of the Rhya- 

 cophilinae and the larvae of Glossosoma are almost 

 always found in clear, cold, fast-flowing streams. 

 The mountain streams of the West are particularly 



Fig. 10:7. Male genitalia of Rhyacophila. a, acropedes, lateral 

 view; b, grandis, lateral; b I# tenth tergite; c, onge//fa, lateral; 

 Cj, tenth tergite; c 2 , aedeagus (,a,b, Ross, 1938; c, Denning, 

 1948b). 



productive, and a high percentage of the known 

 species are from that area. 



Key to Genera" 1 

 Known Larvae 



1. Anal hooks long, large, (fig. 10:56); larvae free-living 

 Rhyacophila Pictet 1834 



— Anal hooks very small; larvae living in cases 2 



2. Front legs attached at anterolateral angle of pronotum 



Glossosoma Curtis 1834 



— Front legs attached at mid-point of lateral margin of 

 pronotum 3 



3. Anal hooks divided into many teeth (fig. 10:5m) .... 



Protoptila Banks 1904 



— Anal hooks divided into 1 large and 1 small tooth 



Agapetus Curtis 1834 and Anagapetus Ross 1938 



Adults 



1. Front tibiae lacking apical spurs 



Protoptila Banks 1904 



— Front tibiae with 2 prominent apical spurs 2 



2. Front tibiae with preapical spur (fig. 10:5Z) 



Rhyacophila Pictet 1834 



— Front tibiae without preapical spur 3 



3. Mesal pair of warts on pronotum nearly touching .... 



Pale agapetus Ulmer 19 12 



— Mesal pair of warts on pronotum well separated .... 4 



4. Hind wing with radial sector 2-branched; male with 

 lateral plate of 5th abdominal segment highly special- 

 ized Agapetus Curtis 1834 



— Hind wing with radial sector 3- or 4-branched 5 



5. Hind wing with radial sector 3-branched, male claspers 

 large, 2-segmented Atopsyche Banks 1905 



— Hind wing with radial sector 4-branched 6 



6. Front wing with callosity; apical spur of hind tibiae 

 modified; pair of small warts on mesoscutellum 



Glossosoma Curtis 1834 



— Front wing without a callosity; apical spur of hind 

 tibiae simple; single transverse wart on mesoscutellum 



Anagapetus Ross 1938 



Genus Rhyacophila Pictet 1834 

 Nearly ninety species of Rhyacophila are known from 



'Modified from Ross (1944). 



