5. Genus Oligotricha Rambur (Ne ur on ia Stephens) 



Full-grown larva. Length 2 0— 24 mm, Frontoclypeus with or without 

 dark median pattern; dorsal stripes near coronal suture not close together. 

 Two wide, dark stripes on pronotum and the membranous parts of 

 mesothorax, metathorax, and abdominal segment 1; they continue in some 

 .. specimens on the following abdominal segments. Gills present on segments 

 1—8. Claw of anal legs with 3 large dorsal denticles. 



Case straight, smooth, made of symmetrical fragments of plants arranged 

 in 6 — 8 forms of spiral. 



Pupa. Length 15 — 18 mm. Frontal sclerite slightly convex anteriorly. 

 Mandibles with short, blunt apex; basal tubercle large, with 2 long setae. 

 Dorsal process of abdominal segment 1 with rounded apex. Anal appendages 

 irregularly rhomboidal, with 4 thick, relatively long setae; ventral 

 appendages of male short, rounded posteriorly. 



Case 30— 40 mm long, with about 10 turns of spiral. 



Mode of life and habitats. Stagnant and slowly running water, small 

 ponds, puddles, peat deposits, and draining ditches. 



Distribution. USSR: European part, northern, western, and central 

 areas, Siberia, the Far East. In addition. Northern and Central Europe, 

 North China, North America. 



Key to Species 



Full-grown larva 



1 (2). Frontoclypeus mainly light, without dark, median pattern 



1.0. striata L. (p. 50) 



2 (1). Frontoclypeus with dark, posteriorly wider median pattern 



2.0. lapponica Hag. (p. 54) 



1. Oligotricha striata Linne (N e u r o n i a ruficrus Scopoli) 



Klapalek, 1893:5-8, Figure 1. - Struck, 1903:121, Plate 1, Figure 4. - 

 Ulmer, 1903:41; 1903b: 189-191, Figures 14-18.- Siltala, 1 904c : 5-6.- 

 Ulmer, 1909:238, 303, Figure 443a.- Lestage, 1921:572-579, Figure 192 a, 

 d, e, j, g, i. - Lepneva, 1940:208. - Hickin, 1944:9-12, Figures 1-9. 



Full-grown larva. Length 20— 22 mm. Sclerotized areas mainly light 

 golden yellow; pattern distinct, brownish. Head (Figure 65) slightly oblong. 

 Frontoclypeus without pattern; anterior -angle areas slightly dark. Dorsal 

 stripes straight, wide, extending from anterior naargin of head to occipital 

 foramen, at first close to frontal sutures, but in area of fork and further 

 posteriorly more distant from the suture, leaving a light area on each 

 side of the coronal suture. Lateral stripes narrow, slightly dark, with 

 dense, large dots which do not reach the occipital foramen. A dark, wide 

 stripe ventrally in each half; a transverse row of 3 large, dark dots on 

 the band, a group of small dots posteriorly (Figure 66). 



50 



