Anterior opening of case truncate, with a projecting dorsal fragment; 

 posterior opening straight, exposed. 



Pupa. Length 18—22 mm. Antennae of female pupae reaching abdominal 

 segment 8, those of male pupae segment 9. Anterior margin of labrum 

 sometimes with minute spinules. Mandibles with narrow distal part; 

 lateral margin slightly convex; median margin almost straight, serrated; 

 lateral setae situated basally, dorsal seta much larger than ventral. 



Wing sheaths reaching end of abdominal segment 4. Midlegs natatorial. 

 Hind legs with sparse setae on tarsal segments 1 or 1—4. 



Gills on abdominal segments 2—7 or 2—8. Holding apparatus on 

 segments 3—7; plates relatively large, hooks as follows: 111:0—4; IV:2— 5; 

 V:3-5+10-21; VI:2-5; VII:2-6. 



Anal rods (Figure 351, B) straight, slightly curved at apex. First 2 setae 

 situated in basal half, the other 2 setae subapically and apically. Sheath 

 of ventral male appendages wide, rounded posteriorly, projecting beyond 

 narrow, bifid penis sheath (Figure 351, A). 



Pupal case shorter than that of larva, 30—40 mm long; large, posteriorly 

 projecting fragments are cut off before pupation; in cases which are longer 

 than pupa, the anterior and posterior sievelike membranes are situated 

 inside. 



Mode of life and habitats. Usually in lakes, among vegetation, 

 in calm water, among reeds, rushes and Scolochloa festucacea in 

 open water. 



Distribution. Northern, western, and central parts of the European 

 USSR, Western and Eastern Siberia, Yakutia, Kamchatka. In addition. 

 Northern and parts of Central Europe. 



10. Limnophllus bipunctatus Curtis 



Struck, 1899:264, 1900:Figure 18.- Ulmer, 1901 :134.- Struck, 1903:88, 

 Plate II, Figure 2. - Ulmer, 1903:52. - Siltala, 1908b: 14, Figure 1. - 

 Ulmer, 1909:262-263, Figure 394.- Lestage, 1921:729, 737, 746, Figure 255d. 



Full-grown larva. Length 16— 18 mm. Main color of head and thoracic 

 sclerites yellowish white,''' punctation distinct, pinkish brown, stripes and 

 spots indistinct. Head almost as long as wide. Frontoclypeus 

 (Figure 352, A) with narrow, brownish stripe near anterior margin, with 

 darker, golden brown areas between anterior and middle frontal setae 

 laterally; wedge-shaped pattern of posterior area consisting of partly fused 

 dots. Dorsal stripes indistinct, beginning behind palps as a narrow, dark 

 stripe which widens near the eye and narrows again posteriorly without 

 reaching fork of frontal sutures; a slightly dark area also in posterior part 

 near coronal suture, where dorsal stripes meet; dorsal stripes separate 

 from frontal sutures all along, leaving a lighter, narrow stripe lateral to 

 frontal sutures; stripes with distinct punctation. Longitudinal rows of 

 large dots on site of lateral stripes. Ventral surface light, yellowish 

 anteriorly, brownish in middle, with a row of 3 dense, large, dark brown dots; 

 large, chestnut brown dots near occipital foramen. Gula slightly dark. 



The color is described from preparations; sclerites are not so light in whole specimens, faintly brownish, 

 and stripes and dots are less distinct. 



255 



