63 



4 (5). Mandibles long, median blade projecting, knifelike. Anterior 



membrane with a few, small holes near dorsal margin 



3. Apataniinae Ulm. (p. 103) 



5 (4). Mandibles of normal length. 



6 (7). Ends of case covered with a small, flat stone above the membrane, 



as in Odontoceridae 2. Neophylacinae Schm. (p. 95) 



7 (6). Ends of case covered with sand grains above the membrane 



5. Drusinae Banks (p. 388) 



8 (3). Apex of mandibles strongly narrowed, usually not serrated. If 



wider and serrated, blade straight, not angular as in Drusinae. 



Gills with 1, 2, or 3 filaments 4. Lim.nophilinae Kol. (p. 177) 



1. Subfamily DICOSMOECINAE Schmid 



Full-grown larva. Length 11— 23 mm. Head oblong. Secondary setae 

 absent. Forelegs similar to mid- and hind legs, but shorter and slightly 

 thicker. Gills of anterior abdominal segments with one or 10—12 filaments; 

 some genera (imania Mart.) without gills. Case made of mineral 

 particles, rarely of plant particles, curved, with flattened ventral side. 



Pupa. Length 11—21 mm. Median blade of mandibles serrated. Dorsal 

 process of abdominal segment 1 deeply concave; presegmental plates with 

 2—3 large denticles, postsegmental plates with 7—10 small denticles. Anal 

 appendages wide, lobe -shaped or thin, rodlike. 



Case as in the larva; anterior and posterior membranes with a varying 

 number of holes. 



Four genera of this subfamily in the USSR: Dicosmoecus McL., 

 Ecclisomyia Bks., Ironoquia Bks., Imania Mart. According to 

 the morphology and ecology of the pre-imaginal stages, all these genera 

 could be placed in different tribes. 



Mode of life and habitats. Phytophagous and detritophagous, 

 living on stony or detritus bottom. 



Distribution. European USSR, Siberia, Far East, Kamchatka, Sakhalin. 

 In addition, Asia, except its southern and southwestern parts. North America, 

 and the western shore of South America. 



Key to Genera 



Full-grown larva 



1 (4). Head uniformly dark. Gills with 1—4 filaments. Case made of 



sand grains or of sand grains and detritus. 



2 (3). Larva large, 22— 23 mm. Gills with 4 filaments 



1. Dicosmoecus McL. (p. 75) 



3 (2). Larva 11— 12 mm long. Gills with one filament 



2. Ecclisomyia Bks. (p. 84) 



4 (1). Head yellowish brown with pattern of dark stripes and spots. Gills 



with 10 or more filaments. Case made of detritus 



3. Ironoquia Bks. (p. 88) 



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