10 shaped like shields or bags. Some of the free -living forms build fixed 

 constructions in the form of long galleries, nets or chambers. 



The suborder Integripalpia has eruciform larvae (Figure 2) with a 

 hypognathous head, * fused abdominal segments separated by shallow 



constrictions; the anal legs are short, 

 and the claws are directed laterally; 

 they live in movable, tubular cases. 



To the same category belong 

 larvae of a transitional type (suberuci- 

 form) with a slightly hypognathous 

 head, deep constrictions between the 

 segments of the abdomen, but with 

 short anal legs as in typical eruci- 

 form larvae. 



Caddis fly larvae undergo 4, rarely 

 5 or 6 molts; the total number of 

 larval stages is usually 5, rarely 6 

 or 7; after completion of its develop- 

 ment, the larva builds a pupal case 

 or modifies and fastens the larval 

 case; it spends a certain period in 

 this case as a prepupa. It molts 

 into the pupa inside the case. 



Caddis fly larvae, except for a 

 few genera (Enoicyla), live in the 

 water. The larvae of some species 

 live in springs or on the banks of 

 water bodies with flowing or spring- 

 water, among humid moss or humid 

 wood debris. The larvae live in very 

 different water bodies, flowing or 

 stagnant, fresh or brackish; they 

 predominate in localities with a 

 sufficiently humid climate and with a 

 well-developed hydrographic network. 



External morphology 



A description of the external 

 morphology of the larva and pupa was 

 given by a number of authors, e. g., 

 Pictet (1834:29-100) (see Klapalek, 

 1888:1-23; Siltala, 1902:1-10, 33-38; 

 1905:34-38,46-48; Ulmer, 1903:9-27, 

 1909:209-213,283-285; Lestage, 

 1921:343-398; Orcutt, 1934; Lepneva, 



FIGURE 1. Campodeiform larva of Rhyacophila 1940:191-223). Nielsen (1942:259— 318; 



sibirica, lateral described the external morphology of 



11 



The hypognathism of the caddis fly larvae is not so sharply marked as in caterpillars of Lepidoptera. 



