Pupal case as in M. longicornis. 



Mode of life and habitats. Vegetation of stagnant and running 

 water bodies; more common in running water than M. longicornis; 

 occurs not only in slow rivulets, but also in creeks and backwaters with 

 more rapid current. 



Distribution. Western, central, and northern parts of the European 

 USSR; northwestern Siberia. In addition, Europe. * 



6. Mystacides sibirica Martynov, larva nova 



Full-grown larva**. Length 8.2 — 10.1 mm long. Main color of head, 

 light yellow; thoracic sclerites, yellowish white; pattern resembling that in 

 M. longicornis but less dark; stripes black or blackish brown; large 

 dots reddish brown. 



Head (Figure 768, A): frontoclypeus without black stripe at anterior 

 margin; anterior pair of dots large, 2nd pair much smaller, 3rd pair small 

 and pale; black stripe in posterior part with a small median incision, and 

 with a wide posterior projection. Dorsal stripes narrow, black anteriorly, 

 blackish brown posteriorly, with 3 dark dots. Stripes along coronal suture 



478 replaced by 2 rows of large, dark dots on slightly darker background; lateral 

 stripes also replaced by large dots; ventral surface with groups of 7 — 8 

 dots near occipital foramen, dots nearest to margin fused. Gula with a wide, 

 dark, median stripe which is sometimes present only in anterior 3rd, other 

 surface almost entirely dark grayish brown (Figure 768, B). 



Pronotum with wide, dark reddish brown, bracketlike pattern with a darker 

 and shorter posterior branch ending in 2 large dark dots; anterior- angle 

 area surrounded by a light stripe and with 2 large, dark spots, each of them 

 formed by 2 dots; a similar spot of 2 fused spots behind the stripe; 4—5 

 large dark dots in middle of posterior margin; posterior margin with a 

 narrow, black line, margin brown with a yellow lateral spot, except for a 

 light median area. 



Pattern of mesonotum (Figure 769) slightly dark, brownish, darker 

 anteriorly with large and small blackish brown dots; a narrow, light brown 

 stripe near anterior margin; a darker area with a large and a small dot 

 near pattern; lateral and posterior part brownish near margin; middle of 

 each half with a curved row of reddish brown dots on light background. 



Legs whitish yellow; mid- and hind femora smoke brown, darker than 

 other segments; dark spots of coxa and distal stripes of mid- and hind 



479 femora, tibiae, and tarsi reddish brown, smaller, and less distinct than in 

 M . nigra. 



Coloration of head and thorax of M. sibirica intermediate between 

 M. longicornis and M.azurea; it differs from the latter in the 

 presence of gills. 



* Early authors (Hagen, Banks) record this species from America; Betten and Ross do not give localities; 

 Batten even states that his material does not include M . nigra (Betten, 1934:281; Ross, 1949:253, 

 Figure 865). 

 "* Description from a specimen from Lake Tal'tsinskoe in the floodplaln of the Angara, 20 July 1945, length 

 10. 1mm, collection of I.M. Levanidova (which also includes a male pupa). Other material from the 

 following localities: 1) coastal area of Sea of Japan, Lake No. 1, 6 August 1927, 7 specimens, length 

 8.2— 9. 0mm, collection of E. F. Gur'yanova; 2) Ussuri Territory, Maikhe Rivulet near village Maikhe, 

 near the bridge, 4 June 1929,4 specimens, collection of P. D. Rezvoi. 



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