Pupa. Length about 17— 18 mm. Antennae reaching abdominal segment 8. 



Mandibles with broad distal part; median blade almost straight. 



Wing sheaths reaching end of abdominal segment 6, Midlegs natatorial, 

 hind tarsi with sparse setae. 



Holding apparatus on segments 3—7; number of spinules: 111:4—5; 

 IV:4; V:5 + 13; VI:4-6; VlI:4-5. 



Anal rods 1,1 mm long, first 2 setae situated in basal quarter, other 

 2 apically and subapically. 



Pupal case shorter than larval case, 30 mm long; anterior and posterior ends 

 covered with interwoven stalks of moss above the sievelike membrane. 



Mode of life and habitats. Small, swampy water bodies with 

 . _^ rich vegetation. 



Distribution. Northern, northwestern, and central parts of the 

 European USSR ; Western and Eastern Siberia, Altai, the Yakutsk area. In 

 addition, Finland, Japan. 



4. Genus Limnophilus Leach 



Full-grown larva. Length 10.5— 28.0 mm. Head wide, short, about as 

 long as wide in most species; coloration either light with a distinct pattern 

 of stripes and dots, or dark, with indistinct bands, or whole head dark, with 

 light spots and dots; dots distinct only in posterior part of frontoclypeus. 

 Mandibles short, black; teeth at distal margin blunt, small. 



Pronotum with distinct X -shaped, median, punctate pattern; anterior 

 third of sclerite light as on other surface, or more or less dark; groove 

 in anterior third sometimes with a dark stripe in middle. Forelegs 

 much shorter than the mid- and hind legs; secondary setae few, present 

 only on coxae and femora. 



Gills on segments 2—7 or 2—8, with 3 filaments on anterior segments, 

 1 or 2 filaments on middle and posterior segments. Tergite of segment 9 

 with few, small, secondary setae; 1—2 setae usually between medioanal setae. 

 Anal legs short, thick; sclerite "b" with large, dark, mediodistal angle seta, 

 and a few thin, small, secondary setae. Claw small, with 1—3 dorsal 

 denticles; setae as usual in subfamily. 



Case made of plant or mineral particles, or of different material: 

 small or large fragments of plants or detritus, arranged regularly 

 (L, stigma) or irregularly, case often very bulky (L. rhombicus); 

 cases made of mineral particles usually have smooth walls with small to 

 medium -sized sand grains, shells of moUusks or Ostracoda, some of them 

 slightly flattened dorsoventrally, flattened ventrally, slightly curved. 



Pupa. Length 9—22 mm. Antennae reaching abdominal segments 7—8. 

 Labrum and anteclypeus divided by a deep groove; labrum with 5 large, 

 hooked setae of about the same length. Distal part of mandible wide 

 basally; median blade serrated, with slightly concave apex. Wing sheaths 

 reaching abdominal segments 4—5. Midlegs natatorial, with dense rows 

 of setae on the tarsal segments 1—4; hind tarsi with sparse setae. 



Dorsal process of abdominal segment 1 large, saddle-shaped, with a 

 deep, median depression between lateral lobes, which bear large, black 

 spinules. Lateral line on segments 5—8, with dense, dark setae. Gills 

 on segments 2—7 or 2 — 8; gills of anterior segments with 3 filaments, as 



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