Young larva. Length in 1st stage 1.3 mm, in 2nd stage 2.0—3.2 mm, in 

 3rd stage 3.2—5.1 mm, in 4th stage 4.5—7.8 mm; width of head in 1st stage 

 0.39-0.41 mm, in 4th stage 0.56—0.65 mm, in 5th stage 0.82—0.92 mm. 

 Sclerites completely light in the 1st and 2nd stages; only posterior part of 

 pronotum with a dark stripe; the light yellow color appears in the 3rd stage, 

 the yellow color in the 4th stage; dark stripes and spots appear on the 

 sclerites of pleuron and anal legs; the mandibles become brownish at the 

 end; a dark border of the pronotum becomes differentiated, and indistinct 

 spots appear on the head and pronotum. Trochantin simple and without 

 process in the 1st stage; a beak- shaped process appears in the 2nd stage; 

 this process has the form of a horn in the 3rd stage; this horn becomes 

 long in the 4th stage, and assumes its definitive fingerlike appearance only 

 in the 5th stage (full-grown larva). Development of the secondary setae 

 of the thorax shown in Table 9 (after Nielsen). 



Claws of young larvae relatively longer than in the full-grown larvae; 

 two basal spines near the seta (Figure 501 ). 



Pupa. Length of male pupae 5.7—6.5 mm, of female pupae 6.7—7.7 mm. 

 First antennal segment with 2—4 lateral setae. Labrum semicircular; 

 3 small light setae near the anterior margin, one of them situated behind 

 the other two. Mandibles brown and long, geniculate at the base, pointed and 

 flattened at the end; blade of mandibles serrated, with 3 large teeth near 

 the apex (Figure 504); outer setae of the same length, situated close 

 together near the basal margin; anterior seta of this group light and curved 

 to the surface of the mandible. Natatorial setae dark, dorsal row situated 

 372 on segments 1 — 3 of the mid-tarsi, ventral row on segments 1 — 2; a few setae 

 are also situated on the 3rd segment. Presegmental plates of holding 

 apparatus present on abdominal segments 3—7; postsegmental plates on 

 segment 5; plates and spinules light brown; number of spinules: 111:5—7; 

 IV:5— 7;' V-4— 7 + 8— 9; VI: 1; VII:l(4); spinules arranged in transverse rows 

 on segments 3—5; the anteriorly-directed spinules on the postsegmental 

 plates of segment 5 are arranged in a posteriorly-curved row, which gives 

 the sclerite a concave, spoon- shaped form; presegmental plates of 

 segments 6 and 7 oblong; spine near anterior margin large, strongly curved 

 posteriorly; segment 7 sometimes with 3 or 4 small additional spines. 

 Anal appendages absent; end of body of female pupae blunt; end of male 

 pupae with distinct, large ventral appendages and penis (Figure 505). 



Mode of life and habitats. Brook and springs with cool water. 

 The larva makes its tubular galleries on stones (Figure 506). 



Distribution. West of the European USSR. In addition, Europe. 



2. Wormaldia subnigra McLachlan 



Siltala, 1903b:6-10, Figure, 1, a-h; 1905:120-121, Figure 29, a. - Ulmer, 

 1909:227-294.- Lestage, 1921 :469-472, Figure 152.- Lepneva, 1940:203. - 

 Philipson, 1953b:57— 62. 



Full-grown larva. Length 7.0—10.3 mm (Figure 507). Head yellowish 

 brown, slightly lighter laterally and vnetrally; anterior projecting margin 

 of the frontoclypeus slightly darker (Figure 508); indistinct dark dots 

 lateral to the epicranial suture and near the occipital foramen. Both parts 

 of the eye situated close together, sometimes fused. Dorsal sclerite of 



415 



