48 



Full-grown larva. Length to 24 mm. Sclerotized areas mainly yellow. 

 Frontoclypeus (Figure 70 ) with dark brown median pattern, wider posteriorly, 

 almost adjoining frontal sutures, with a transverse row of light dots 

 posteriorly. Dorsal stripes wide, with dark dots posteriorly; dark spots 

 and dots ventrally. Labrum and mandibles as in O. str iat a. 



Number and arrangement of gills ofO. lapponica 



Segment 



Dorsal 



Pleural 



Ventral 



1 









1 

 1 



2 



1 

 1 









3 



1 

 1 









4 



1 



1 









5 



1(0) 



1 









6 







1 



1 







7 





 1(0) 









8 











Pronotum (Figure 7l), as in O. st r i at a, with wide, dark oblique stripe, 

 which is wider in the middle and with dark dots; large groups of dark dots 

 lateral to the stripes, 2—3 dots in the middle. 



Mesonotum, metanotum, and abdominal segment 1 with 2 parallel, 

 longitudinal, wide stripes which, together with the bands of pronotum and 

 the dorsal bands of the head, form a pattern characteristic for the genus. 

 Legs as in O. s t r i a t a. 



Gills on segments 1—8. 



Postsegmental, pleural gill of segment 2 covered with fine hairs, in 

 contrast to ©.striata. 



Claw of anal legs with 3 dorsal denticles. 



Case made of spirally arranged fragments of plants. 



Pupa. Length about 20 mm. Antennae reaching end of abdominal segment 

 4. Frontal process and labrum as in O. striata. Mandibles with short, 

 blunt apex, outer tubercle long, both setae long (Figure 72). 



Dorsal process of abdominal segment 1 as in O. striata, with straight 

 or concave posterior margin. Spinules of holding apparatus: 111:3—6; 

 lV:3-8; V:5-8+5-13; VI:5-8; VIl:3-8. Gills on segments 2-8. 



Anal appendages (Figure 73) short, 4 terminal setae black, alnaost of the 

 same length. 



Case usually 20—40 mm long, its anterior end covered by interwoven 

 plants. 



55 



