bottom and the life conditions of the bottom organisms; the whole litho- 

 rheophilic fauna disappears, including the potamobionts. Neureclipsis 

 bimaculata is the most tolerant of the potamobionts; this species 

 develops in large numbers in parts of the river which have retained their 

 original current, e. g., near the inflow into the Tsimlyanskii Reservoir.* 



The new fauna of Trichoptera of reservoirs consists of the fauna of the 

 riverbanks and plant thickets; some of the most eurytopic species are able 

 to live in water reservoirs. On the other hand, species which were rare and 

 represented by isolated specimens in rivers may develop abundantly in 

 reservoirs, e. g., larvae of Ecnomus tenellus and Oecetis sp. Some 

 of the limnophilic species of reservoirs enter from the river floodland or 

 from lakes. 



From the Rybinsk Reservoir, which was built in 1941, there have been 

 26 species of caddis flies recorded, including Agraylea multipunctata, 

 Neureclipsis bimaculata, Cyrnus flavidus, Ecnomus tenel- 

 1251us, Agrypnia pagetana and 3 species of Oecetis (O. furva, 



O. lacustris, O. ochraceae), Leptocerus senilis, Triaenodes 

 bicolor, Mystacides longicornis, Molanna palpata (Zarechnaya, 

 1959a:179-186). 



Limnophilus rhombicus and Oecetis ochracea were found 

 in the Ucha Reservoir. Large numbers of Ecnomus tenellus occur 

 in small reservoirs in the Krasnodar Territory, e. g., in the Tshchikskoe 

 Reservoir; this species is common in small reservoirs also in other 

 localities. Large numbers of Oecetis ochracea occur in the 

 Shapugskoe Reservoir. 



Cyrnus flavidus, Ecnomus tenellus, Triaenodes bicolor, 

 Oecetis lacustris, Mystacides longicornis and Molanna 

 angustata occur in a small reservoir on the Embulatovaka River, 

 tributary of the Ural River in the Ural Region in West Kazakhstan. In the 

 Farkhad Reservoir of Middle Asia Ecnomus tenellus predominates; 

 Oxyethira sp. and Agraylea pallidula predominate in plant 

 thickets. 



Of the rheophiles which were found in the Oredezha River before the 

 dam was built, the following species disappeared from the small Vyritskoe 

 Reservoir: Rhyacophila nubila, P 1 e c t r o c n e m i a c o n s p e r s a, 

 Neureclipsis b i m a c ula t a, Hy d r o p s y c h e pellucidula, 

 Chaetopteryx sahlbergi, Lepidostoma hirtum, Brachy- 

 centrus subnubilus, Sericostoma personatum and Goer a 

 pilosa; P o ly c e n t r o pu s f la v o m a c ul a t u s and Potamophylax 

 stellatus did not disappear. Of the species living in plant thickets and 

 parts with a silt-sand bottom, the following species remained in the 

 reservoir: Ithytrichia lamellaris, Cyrnus flavidus, Holo- 

 centropus picicornis, Molanna angustata, Phryganea 

 striata, Limnophilus rhombicus, L. flavicornis and G r am - 

 motaulius atomarius; Oecetis furva and Nemotaulius 

 p u n c t a t ol i n e a t u s appeared again (Shcherbina, 1958:95—96, 104—105). 



According to Ts.I. Ioffe. 



17 



