Mode of life and habitats. The species described live in stagnant 

 waters, among vegetation, often in large numbers. 



Key to Species;, 



Fnll-grown larva 



1 (2). Head yellowish brown dorsally; anterior of the 3 pairs of dots in 



anterior part of frontoclypeus, paler and smaller than the other two; 

 case thin- walled, yellow or yellowish brown; European 



USSR 1. L. tineiformis Curt. (p. 614) 



491 2 (1). Head pinkish brown dorsally; anterior of the 3 pairs of dots in 



anterior part of frontoclypeus, larger than the others; case thick- walled, 

 brownish, often with fine sand grains posteriorly; Maritime 

 Territory 2. L. valvatus Mart. (p. 621) 



1. Leptocerus tineiformis Curtis 



Struck, 1900: Figure 40; 1903:70, Plate III, Figure 13. — Ulmer, 1903: 

 102— 103, Fig. 66; 1909:250, 309, Figures 378,455.— Lestage, 1921 :650— 655, 

 Figures 226a, d,h, i, 227, 228.— Lepneva, 1940:210— 211. — Hickin,1953: 

 74—76, Figures 1—8. 



Full-grown larva. Length 8 mm. Head (Figure 788, A, B) oblong, 

 yellowish brown and whitish and with reddish brown dots ventrally and at 

 occipital foramen. Sensilla of antenna narrow apically; seta short. Fronto- 

 clypeus narrow, with small lateral indentation; anterior part slightly darker at 

 anterior margin and laterally, with 3 pairs of large dots, those of the anterior 

 pair slightly closer together, paler, and smaller than the others; pattern in 

 posterior part situated near tentorial pits, formed by 3 large dots and a 

 smaller dot before them. Area of coronal suture white, suture absent. 

 Dorsal stripes narrow, indistinct; 3 large dots lateral to posterior part of 

 frontal sutures, 2 other dots further posteriorly; anterior and posterior dot 

 of row smaller and paler than others. Lateral region with a group of 5 small 

 492 dots dorsal to white stripe and 2 large dots ventral to stripe; a similar dot 

 laterally on ventral side; distinct brownish areas on white background 

 , lateral to gula. Gula white, triangular, dark brown anteriorly; posterior 

 angle broadly rounded; large lateral sclerites fused behind the gula; gular 

 suture absent. Anterior margin of head with a strong, pointed, spine-shaped 

 process near ventral articulation of mandible (Figure 788, C). Setae thin, 

 yellowish or light brown. Median and intermediate anterior-margin setae 

 small, situated close together; lateral seta slightly larger, situated on the 

 suture; anterior frontal seta short, intermediate and posterior frontal setae 

 longer, situated near the tentorial pit lateral to the pattern. Setae 9 and 11 

 almost equally long, situated medial to eye; seta 10 large; seta 7 slightly 

 shorter; setae 14 and 12 larger, situated in posterior part; setae 13, 15, and 

 16 moderately long; seta 18 slightly shorter, situated behind the others; 

 ventrally: seta 8 short, light, seta 18 small; the greater length of setae 11 

 and 13, which are usually short is characteristic for Leptocerus. 



614 



