2 (l). Median dark stripe of frontoclypeus nearly uniformly broad; margins 

 of sclerite near bifurcation of frontal sutures slightly dark. Light 

 median longitudinal stripe on dorsum of thoracic segments absent 

 or indistinct 2. A. palpata Mart. (p. 539) 



1. Arctopsyche ladogensis Kolenati 



Siltala, 1905:111-114; Figure 26.- Lepneva, 1928:28-31, Table 1, 

 Figures 1—11.— Flint, 1961:6-8, Figures 1-10. 



Full-grown larva. Length 18— 20 mm. Head slightly oblong (Figure 666), 

 slightly flattened dorsoventrally; ratio of length to width 1:0.8. Head 

 grayish yellow; stripes and spots brown, with coarse dark dots. Fronto- 

 clypeus wide, with deep lateral indentations. The truncate wedge-shaped 

 gula extends along the whole head, dark anteriorly, posteriorly and laterally. 

 A broad dark brown median stripe which is narrower in the middle on the 

 frontoclypeus; it is rhomboidal posteriorly; a transverse curved row of 

 small dots in the posterior part of the stripe; a row of 4 or 6 dots in the 

 anterior third; 1 or 2 dark dots lateral to the stripe in the middle; lateral margins 

 466 narrowly dark anteriorly and posteriorly, light in the middle; posterior 



angle of sclerite light; dark lateral stripes on the posterior part sometimes 

 contiguous with the lateral angles of the rhomboidal part of the stripe. 

 Dorsal stripes of head broad, extending from anterior to posterior margin 

 of head, closely contiguous to the frontal sutures and situated at a distance 

 from the coronal suture; 3 light dots in the middle; posterior part with 

 rows of fine dark dots. Space between median and dorsal stripes of head 

 forming a characteristic light fork- shaped figure. Lateral stripes broad, 

 with fine dark dots, which are often connected with the dorsal dots. Large 

 groups of coarse dots ventrally at the sides of the posterior part. Dark 

 stripes and spots (also light background in some places) with small, curved, 

 light, covering setae which have distinct alveoli (Figure 668). 



Primary lateral seta and intermediate seta of the anterior-margin setae 

 of the frontoclypeus very thick, dark and long; median seta shorter, lighter 

 and slightly thinner; near it an almost equal or longer secondary seta; 

 3 or 4 similar long setae situated near and between the other two anterior - 

 margin setae; several light, soft, small setae at the anterior margin. 



Frontal setae light; anterior frontal seta slightly curved inward; several 

 similar, small, light, secondary setae near it; middle frontal seta light, 

 short, situated near curvature of the frontal sutures, inside the dark dot; 

 posterior frontal seta indistinguishable from the sparse secondary covering 

 setae. Clypangulus dark, with thick, dark, short setae; 1—5 dark and light 

 additional setae posterior to it. The primary seta 9, near the frontal suture 

 4 67 is the thickest, darkest and longest seta of the head; it is slightly longer 

 than the long anterior-margin setae; posterior to it, near the suture, at a 

 marked distance from the eye, is the small dark seta 11; seta 7 dark, 

 shorter and thinner than seta 9, situated near the dorsal articulation of the 

 mandibles; the small antennal tubercle with 3 thin light setae is situated 

 anterior to seta 9 near the margin; the similar, thin seta 8 is situated 

 more ventrally near the margin; the short seta 10 is situated laterally, 



530 



