Claw (Figure 595) narrow, long, curved at almost a right angle; basal 

 part of claw shorter than the apical part, which has a comb of spinules 

 ventrally. Setae 1 and 2 thin and long, like seta 6; seta 3 shorter; seta 4 

 thin and light; seta 5 forming a microscopic light spinule; seta 8 short and 

 strong, spinelike and light; seta 7 absent. 



Pupa. Length 5.8— 6.4 mm, spindle-shaped. Antennae of female pupae 

 reaching the end of abdominal segment4,of male pupae segment 7 or the 

 beginning of segment 8. Clypeus with 3 thin setae laterally; median seta 

 small. Labrum short, broad; 2 strong, relatively long setae in the middle 

 of each half of the labrum; 3 strong lateral setae and a small thin median 

 seta laterally, near the margin. Distal part of mandible narrow, straight, 

 pointed; blade finely serrated; short, basal outer setae straight, of the same 

 length. 



Wing sheaths reaching end of segment 5 or beginning of segment 6. 

 Mid-tarsi with sparse natatorial setae. Presegmental plates present on 

 segments 3—8, postsegmental plates on segment 5; sclerites at base of 

 spinules thin, indistinct; rows of spinules on presegmental plates shorter 

 than on postsegmental plates, but the spinules are longer; number of spinules 

 as follows: 111:8-10; IV:9-12; V:6-7; VI:8-9; VII:5-6; VIII:5-6; rows on 

 postsegmental plates containing 12—20 anteriorly-directed spinules. 



Sides of segments 6—8 and 9 with dense dark reddish brown hairs. 

 Segments 8 and 9 narrow; segment 8 short; lateral lobes covered with 

 numerous black setae at the end of segment 9 in both sexes; these setae 

 are longer in females than in males. 



Pupa lying in a grayish cocoon of loose tissue; cocoon enclosed in a 

 case of irregular form, made of coarse and fine sand grains; case attached 

 to a stone or other objects. The remarkable characteristic of the case is 

 the presence of round filtering sieves near the anterior and posterior end; 

 these sieves are of the same type as in the tubes of Integripalpia. Length 

 of case 7—9 mm. 



Mode of life and habitats. Stagnant and slowly running water; 

 mainly in lakes, often in reservoirs and water bodies in floodlands; they 

 occur in plant thickets in rivulets and rivers in the plains; they are known 

 from lakes in Karelia, lakes in the central parts of the European USSR, 

 lakes in the Urals and the Caucasus, Lakes Zaisan, Issyk Kul and Khanka, 

 lakes of the southern Sakhalin, and is common in reservoirs. 



Distribution. Whole European USSR, includingthe Caucasus, Crimea and 

 Urals, Middle Asia, Far East, southern Sakhalin. In addition, Europe, North 

 Africa, Asia Minor, Iran, India, Tibet, China, Taiwan, Japan. 



VIII. Family PO L Y C E N TR O P O D I D A E Ulmer 



Full-grown larva. Length to 22 mm. Body slender, slightly dorso- 

 ventrally compressed. Frontoclypeus broad, with deep lateral indentations; 

 gula short, broadly triangular. Setae of head thin; only primary setae 

 present. Pronotum sclerotized; meso- and metanotum membranous. Legs 

 with numerous secondary setae. Tracheal gills absent; 5 anal gills. Anal 



legs long. Claw long. 



472 



