running environment is accompanied by reconstruction of the case with 

 replacement of the light plant material with heavier tree detritus. The 

 case of the American species N. hostilis Hag. is similarly covered with 

 vegetable fragments, arranged mainly longitudinally (Lloyd, 1921:43, 

 Figure 50). 



Pupa. Length 22—24 mm. Antennae reaching end of segment 7 or 

 beginning of segment 8. Anteclypeus and labrum yellowish brown; 3 setae 

 of anteclypeus dark brown, thin, moderately long; seta 1 of labrum thick, 

 small, light, curved inward, other 5 setae black, curved at end, arranged 

 in 2 rows of 2 and 3 setae. Mandibles reddish brown, distal part with 

 broad base, median blade straight, serrated. Wing sheaths reaching 

 abdominal segment 5; sheath of fore wings with deep indentation at distal 

 margin. Midlegs of natatorial type; comb with golden brown setae on 

 tarsal segments 1—4, setae of dorsal row slightly longer and denser than 

 ventral setae; segment 1 of hind tarsi also with sparse setae. 



Dorsal process of abdominal segment 1 brown, its distal margin coarsely 

 rugose, blackish; distal lobes of the process with thick black spinules 

 lateral to saddle -shaped depression. Holding apparatus on segments 3—7, 

 number of hooks : 111:2-3; IV:3; V:3-4+ 19-21; Vl:3; V1I:4; plates of 

 segment 3 asymmetrical, much smaller than the others, left sclerite in form 

 of a large sclerotized dot and much smaller than the right. Lateral line 

 from posterior margin of segment 5 to segment 8, where setae of right 

 and left rows are dense ventrally, dark grayish brown, and almost touch 

 each other. 



Sheath of male genitalia in form of 2 small inner lobes and 2 larger 

 outer lobes. 



Anal rods dark brown, tapering distally, slightly wider at the end; setae 

 thick, black, the first situated basally, the 2nd in the basal third, the 3rd 

 and 4th situated apically and subapically. 



Pupal case attached at anterior end; anterior and posterior end rounded and 

 protected by small particles of detritus (Figure 257, D). The sievelike 

 membrane at anterior end is slightly larger than the posterior membrane 

 and has numerous small holes; posterior membrane with fewer, but 

 larger, holes (Figure 257, E, F). 



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

 overgrown biotopes, on plants and on bottom among vegetation; older 

 stages on bottom in open environment. 



Distribution. USSR: Sakhalin, Kurile Islands, Maritime Territory, 

 Khabarovsk area. In addition. North China, Japan. 



2. Genus Glyphotaelius Stephens 



Full-grown larva. Head with dark, T-shaped pattern on frontoclypeus; 

 dorsal stripes indistinct. Anterior third of pronotum dark, middle of 

 groove no darker than the other part. Tergite of abdominal segment 9 

 with distinct, dark, anterior, submarginal spots. 



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

 abundant detritus on bottom. 



191 



