Mode of life and habitats. Lakes, sometimes near mouth of slow- 

 rivers; in calm, shallow water, on a bottom of sand with silt, or sand with 

 detritus. 



Distribution. The European USSR, Siberia (not common). Maritime 

 Territory. In addition, Europe. 



IX. Family LEPTOCERIDAE Leach 



Full-grown larva. Usually small, the largest species not longer than 



12 — 14mm, small species 5.0 — 8.5 mm. Head and prothorax (in some species 



also mesothorax) equally wide; 

 metathorax wider than mesothorax 

 and following abdominal segments. 

 Head usually slightly oblong, in some 

 species slightly wider than long; 

 large lateral sclerites of these 

 species with characteristic, 

 suturelike, light lines which divide 

 the surface into several distinct 

 areas. Antennae situated near 

 anterior margin, forming an elevation 

 with a long sensilla and with a short 

 distal seta as in Hydroptilidae; eyes 

 some distance from anterior margin, 

 sides of frontoclypeus concave or 

 Vvfith a shallow indentation in the 

 middle. Seta 17 usually long. Gula 

 of varying form, reaching posterior 

 margin of head, sometimes fused with 

 large lateral sclerites. 



Labrum with deep tuberculate 



median indentation. Mandibles short and wedge-shaped in most species; 



flat, long, without ventral blade in Oecetis. Submentum absent; segments 



2—3 of maxillary palps fused. 



Pronotum and mesonotum sclerotized, mesonotum sometimes incompletely; 



metanotum membranous, sometimes with small tergites. 



Midlegs and especially hind legs much longer than forelegs; femora 



divided, tibiae or tibiae and tarsi sometimes divided; legs with rich 



secondary chaetotaxy. 



Abdominal segment 1 with dorsal and lateral processes. Lateral line 



thin, with short hairs, on segments 3 — 7. Gills single or with several short 



filaments. 



Segment 9 with small tergite; anterior-margin setae well developed, 



situated close to medioanal setae; anal legs short, wide; claw small, with a 



dorsal denticle. 



Case conical, straight or curved, made of sand grains, rarely of plant 



fragments. 



Pupa. Body narrow; antennae long, coiled several times around posterior 



end of body. Labrum of varying form, often with a small, median process at 



FIGURE 701. Molannodes tincta Zett 

 Larval case, dorsal (A) and ventral (B) 



5125 



540 



