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Pupa 



1 (4). Gills with one or 4 filaments. Anal appendages short, lobe-shaped. 



Case made of sand grains. 



2 (3). Length 19—21 mm. Gills of anterior segments with 4 filaments. 



Anal appendages rounded, lobe -shaped. Case made of large sand 



grains, slightly curved, narrower posteriorly, 23— 24 mm long 



1. Dicosmoecus McL. (p. 75) 



3 (2). Length 11— 12 mm. Gills with one filament. Anal appendages 



pointed, lobe -shaped. Case made of detritus, 12— 13 mm long 



2. Ecclisomyia Bks. (p. 84) 



4 (1). Gills with 10—12 filaments. Anal appendages in form of small, 



narrow rods. Case made of detritus 3. Ironoquia Bks. (p. 88) 



1. Genus Dicosmoecus McLachlan 



Full-grown larva. Length to 23 mm. Head and thoracic sclerites dark, 

 with fine light lines and dots. Gills of anterior abdominal segments with 4 

 filaments. Case made of sand grains, or sand grains anteriorly, detritus 

 posteriorly, slightly curved. 



Pupa. Length 16— 21mm. Mandibles with straight, denticulate medium 

 margin. Gills as in the larva. Anal appendages rounded, lobe -shaped. 

 Case attached at the anterior end. 



Mode of life and habitats. Mountain brooks and rivulets, 

 oligotrophic lakes. One species inhabits small, slow brooks in plains, 

 or drainage ditches with a slow current. 



Distribution. Southeastern part of European USSR, Siberia, Altai, 

 Sayans, the Far East, Kamchatka, Sakhalin. In addition, Japan, North 

 America. 



1. Dicosmoecus palatus McLachlan 

 Lepneva, 1949: 176—179. 



Full-grown larva. Length 22—23 mm. Head oblong (Figure 106). 

 Frontoclypeus : sides lighter than middle anteriorly, brownish near anterior 

 margin, with 3 indistinct dark dots in the middle; 3 such dots in the middle 

 on each side before curvature of frontal sutures; posterior part with large, 

 wedgelike pattern of light dots. Similar dots on dorsal and lateral stripes; 

 large groups of light and dark dots ventrally on each side. Gula triangular, 

 long (Figure 106, B). 



Median and intermediate anterior -margin setae reddish brown, large, 

 the intermediate slightly longer; lateral seta light like the anterior frontal 

 seta, curved inward, procumbent; middle frontal seta dark, long, posterior 

 frontal seta short, light. Setae 9, 14, and 15 long, 9 and 14 dark brown, 

 thick; 15 lighter and thinner; seta 11 short, thin; seta 7 slightly larger; 

 seta 10 light, smaller; seta 12 moderately long, brown; setae 13 and 16 

 light, 16 larger, curved inward; seta 17 large, dark. 



75 



