450 Pupal case 9—11 mm long, shapeless, made of loose tissue with a 



covering of plant fragments; pupa lying in a cocoon of light loose tissue. 



Mode of life and habitats. Plant thickets in small stagnant 

 water bodies. 



Distribution. Western, northwestern and central region of the 

 European USSR. In addition, Europe. 



4. Genus Cyrnus Stephens 



Full-grown larva. Length 11 — 14 mm. Integument delicate, almost 

 transparent; sclerites light yellow, with weakly shaded and distinct punctate 

 pattern. Dorsal stripes of head short, narrow or absent. Abdomen with 

 secondary lateral setae not only on segments 2—8 but also on segments 1 

 and 9; secondary ventral setae present on segments 8 and 9. Anal legs with 

 numerous long setae; claw ventrally with better marked spinules than in the 

 preceding genera, with 4 small, light, subapical denticles. 



Pupa. Length 6—7 mm. Antennae long, reaching segments 7—8 or end of 

 abdomen. Lateral seta of anteclypeus less short than in the preceding 

 genera. Mandibles sickle- shaped, blunt. Tibiae and tarsi of midlegs broad, 

 natatorial setae present on fore and mid-tarsi. Plates of holding apparatus 

 present on abdominal segments 3—8; gills present on segments 2—7 or 2—6. 

 Anal lobes broad, rounded, with numerous dark setae. 



Case 9.0—12.5 mm long, with loose walls covered with plant fragments, 

 rarely with fine sand grains. Pupa lying in a grayish sheath. 



Mode of life and habitats. Predacious; building capturing 

 funnels. Living in slowly running and stagnant water, on the bottom or 

 among vegetation. 



Distribution. European USSR, the Caucasus, in Western and Eastern 

 Siberia (rare). In addition, Europe, Iran. 



Key to Species 

 Full-grown larva 



1 (2). Head dorsally with a distinct characteristic pattern (Figure 655); 



punctate pattern of pronotum indistinct 



1. C.flavidus McL. (p. 511) 



2 (l). Pattern of head different; dots on pronotum distinct. 



3 (4). Head with dots and with distinct dark dorsal stripes lateral to the 



frontal sutures 2. C. trimaculatus Cart. (p. 517) 



4 (3). Head only with a punctate pattern, without stripes 



3. C. insolutus McL. (p. 518) 



Pupa 



1 (4). Gills present on abdominal segments 2—7. 



2 (3). Antennae moniliform in the basal part . . .1. C.flavidus McL. (p. 511) 



510 



