346 



Case made of secretion, yellow or yellowish brown, laterally compressed; 

 its end forms a neck; the case differs markedly from the complete case 

 in the early stages of construction (Figure 44l); the sides of the latter 

 are slightly concave posteriorly. 



Young larva. Length of freshly hatched larva 0.55 mm; ratio of head, 

 thorax and abdomen 10:14.5:17.5; width of head in 1st stage 0.11 mm; in 

 the 2nd stage 0.14 mm, in the 4th stage 0.2 mm. The sclerites are pale in 

 the'first two stages (Figure 442); the sclerites of head, thorax, legs and 

 abdomen are buff yellow, with a gray tone in the 4th stage; anal legs light 

 yellow. 



Seta 9 on the head longer than the others. Mandibles short; denticles 

 on the blades of the left mandible distinct; blades of right mandible each 

 with two teeth (Figure 443). The development of the secondary chaetotaxy 

 of the dorsal sclerites of the thorax is shown in Table 6. 



TABLE 6 





Stage 



Setae 



1st 



2nd 



3rd 



4th 



5th 



Pronotum 



Black anterior- margin seta (M) . . . 

 Yellow anterior- margin setae (m) 



1 

 

 

 

 4 



1 



1 



1 

 1 

 

 



4 



1 

 1 



1 



1 

 1 

 1 

 4 



1 



1 



2 

 1 

 (3)4 

 1 

 4 



2 



2 



3 

 1 

 (3)4 

 2 

 5 



Mesonotum 

 Metanotum 



3 

 3 



Tibiae of midlegs of the lst-stage larva with a large distoventral process 

 (Figure 444); midlegs and hind legs much longer than forelegs; length ratio 

 of legs 46:100:103. 



Tergite of abdominal segment 1 small in the 1st stage, forming a small 

 bridge between the 2 medioanal setae of the segment; additional small 

 lateral tergites are present on segments 2—8 in addition to the median 

 tergite. 



The sclerite of abdominal segment 9 covers about 1$ of its dorsal surface. 

 The extremely long intermediate distal seta of the basal segment of the 

 anal legs of the 1 st-stage larva (Figure 442) of Ox.costalis is twice as 

 long as the larva; the lateral seta is almost as long as this seta in the 4th 

 stage. Claws of the young larva long and thin; setae 1,4 and 5 absent 

 (Figure 445). 



382 



