Orthotrichia tetensii extends the walls of its case by weaving light 

 processes at the sides; these processes are connected on the dorsal side 

 and with the large adhesive disk at the ventral side. 



The pupal cases of Philopotamidae (Wormaldia) resemble the cases 

 of Rhy a c o phi la, but they are smaller and their building material is not 

 so densely connected; the whole structure is looser; its walls, which 

 consist of small stones and sand grains, are smoother. The sand grains 

 and stones form the upper layer of the inner wall of the case; the base of the 

 case is attached to a stone. The cocoon of the pupa is transparent and 

 delicate; its ends are attached to the wall of the case; there are several 

 small openings at the places of attachment; the ends of the cocoon near 

 the openings of the case are especially thin-walled. There are no other 

 ventilation holes. 



The cases of the pupae of Stenopsychidae, which live in brooks and 

 streams, are solidly built of large sand grains or small stones (Figure 145). 



The larvae of Psychomyiidae build a loose pupal case of silk which they 

 cover with sand grains or small stones on the outside; there are numerous 

 openings at the anterior end and at the base of the case; the openings at the 

 posterior end are less numerous (Figure 146, B, C); the position of the 

 openings is connected with the morphology of the pupa and its cleaning 

 apparatus (Figure 146, A). 



The domelike cases of the pupae of Polycentropodidae are situated on 

 stones, plants and pieces of wood; they consist of loosely connected sand 

 grains, small stones or fragments of plants. At the anterior and posterior 

 ends of the case are relatively large openings covered with stones or plant 

 fragments (Figure 147). The cocoon is loosely attached to the walls of the 

 case; it consists of loosely woven, wide-meshed silk tissue. It is easier 

 to tear the loosely built walls of the case and the thin cocoon of the pupae of 

 Polycentropodidae than the strong walls and cocoons of Rhyacophilidae and 

 Glossosomatidae; the mandibles of the pupa are less massive and are 

 without serrations or teeth. 



The larvae of Hydropsyche (Hydropsy chidae) cover the pupal case 

 with small stones, gravel or sand. The cases are attached to stones, pieces 

 of wood, twigs or other objects (e.g., shells of mollusks). Numerous 

 openings are situated at the posterior and anterior ends of the case 

 (Figure 148). 



Annulipalpia build characteristic, closed pupal cases with ventilation 

 holes. Integripalpia pass the pupal stage in the larval case; they close the 

 ends of the larval case with a membrane before pupation; this membrane is a 

 coarse-mesh net or has one or several openings which are round or slit- 

 like; the membrane of the posterior end of the larval case is replaced by 

 a new pupal membrane with one or several openings. 

 97 The pupae of species living in stagnant water with large cases covered 

 with large, projecting plant fragments, e. g., Limnophilus stigma, 

 L. rhombicus, L. flavicornis, lie free on the bottom or are loosely 

 attached to plants or detritus particles; the pupae of Grammotaulius 

 signatipennis, which live in shallow water overgrown with plants, swim 

 on the surface in their short massive cases. Most of the species of 

 Integripalpia which live in running and stagnant water attach their cases to 

 objects before pupation (Figure 149); they alter them to some extent and 

 sometimes even camouflage them. 



