116 In some springs in the Amur basin, e. g., in the Mitriev spring (a limno- 

 cren with cold springs at the bottom and with a temperature of 4.8°) were 

 found numerous larvae of Apatania sp.; there were 180 specimens perm , 

 i. e., a biomass of 3.8 g/m (Klyuchareva, 1952:366). 



Running water 



Mountain streams and brooks. Sadovskii showed (1946:133— 161; 

 1948:21—49) that for the small tributaries of the upper and middle Kura 

 small mountain rivers and brooks have a rich bottom fauna, especially of 

 insects, including caddis flies. The rich rheophilic fauna in these water 

 bodies (defined as "polytrophic ventilated waters") (Sadovskii, 1946:133) 

 is caused by a combination of favorable conditions: transparent water 

 saturated with oxygen (it becomes turbid for only a short time during the 

 torrential floods in summer), a solid, stony bottom of boulders, slabs or 

 pebbles with numerous shelters for animals, and abundant food for 

 phytophages and detritophages (algae and plant detritus). The caddis fly 

 fauna of mountain streams resembles that of mountain brooks but is not 

 so rich. 



Many streams and brooks of the north and northwest European USSR 

 (Karelia, in the Clint Region), and in the northern and central Urals, 

 resemble mountain streams. The following species of Annulipalpia are 

 common in them: Rhyacophila nub il a, Hy d r op t i 1 a sp., W o r m a Id ia 

 subnigra, Polycentropus flavomaculatus, Plectrocnemia 

 conspersa, Hydropsyche angustipennis and H. pellucidula; 

 the following Integripalpia occur in them: Apatania zonella, 

 A. wallengreni, Potamophylax stellatus, Halesus tesselatus, 

 H. int e r punct atu s, Chaetopteryx villosa, C h. sahlbergi, 

 Silo pallipes, Notidobia ciliaris and Lepidostoma hirtum 

 (Lepneva, 1928:102—103; 1953:187—191). Rheophiles which avoid rapid 

 streams such as Anabolia soror, Anabolia furcata, Chaetop- 

 teryx sp., Goer a pilosa occur in brooks and parts of streams with a 

 slow current. 



Rhyacophilidae are abundant in brooks and streams of the Caucasus. 

 These are the same species which occur in rheocrens, i. e., the larvae of 

 Rhyacophila forcipulata, Rh. bacurianica and often large 

 numbers of Rh. vicaria and R h. s u b o v a t a; in Armenia and Transcaucasia 

 occur Rh. subnubila, Rh. aliena and Rh. cupressorum in some 

 localities and rarely, in warmer brooks, Rh. abchasica and Rh. clava- 

 lis. Glossosoma unguiculatum and G.capitatum occur on the 

 lower surface of stones almost completely with their pupal cases in some 

 localities; Agapetus caucasicus and A. truncatus are also 

 common. Philopotamidae are represented by Philop otamu s tenius 

 and Dolophilodes ornata, rarely by Wormaldia subnigra. 

 Psychomyiidae are represented in warmer brooks species of Tinodes 

 (T. adjarica, T. turbulent a, T. sancta); Plectrocnemia 

 latissima (Polycentropodidae) is common; in brooks and streams occur 

 many specimens of Hydropsyche instabilis, H. cornuta, H. acuta. 

 The family Beraeidae (integripalpia) is represented by Ernodes saltans, 

 E. palp at a; the family Limnophilidae is widely represented by Apatania 



107 



