margin. Anal rods (Figure 132) very small, hard and denticulate at the 

 end, each with 3 setae which are longer than the rod: one median basal, 

 2 subapical, all thick, strong, dark. Ventral appendages of male pupa 

 obliquely truncate, penis sheath bifid. 



Pupal case as that of larva; anterior and posterior ends covered with 

 flat plant particles; anterior and posterior membranes with small holes. 



Number of gill filaments in I. dub i a 



Segment 



Dorsal 



Pleural 



Ventral 



1 



7-8 







7-16 



2 



22-23 

 24-25 





7 



12-18 

 21-22 



3 



20-22 

 19-21 



9 





14-15 

 22-23 



4 



12-14 

 11-13 







10-12 

 19-20 



5 



10-11 

 9-11 







9-10 

 11-12 



6 



8-9 

 10-11 







7-8 

 7-8 



7 



8-9 

 10-12 







7-8 

 13-14 



8 



5-6 







4-7 



Mode of life and habitats. Feeding on detritus in overgrown, 

 ditches, and in brooks and streams with a slow current; the pupa probably 

 lives outside the water.* 



Distribution. Northwestern, western, and central parts of European 

 USSR. In addition. Central and Northern Europe. 



2. Subfamily NEOPHYLACINAE Schmid 



Full-grown larva. Medium -sized, 11— 14mm long. Head oblong, bent 

 ventrally; eyes almost in middle of head; antennae close to anterior 

 margin; frontoclypeus large, with large, wide, anterior part, and narrow 

 posterior part; gula narrow. 



Labrum with broad, membranous, anterior margin. Mandibles long, 

 without teeth; brush of chaetoids in median depression of mandible. 



Pronotum long, its anterior margin projecting and covering head. 

 Mesonotum markedly smaller. Anterior and posterior pair of median 



Large numbers of full-grown larvae occur in road ditches in the Zaluch'e area in the Kalinin Region. 

 Although the larvae were ready for pupation, we did not find any pupae after the larvae had disappeared. 



95 



