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FIGURES 106-110. Larval cases covered with detritus, plant and animal 

 fragments: 



106 - cases of Li m no phi 1 u s: L. s t ig m a (A, B), L. f 1 a vi c or ni s (C, D); 



107 — case ofGanonema extensum (after Levanidova); 108 — case 

 of Crunoecia irrorata (after Nielsen); 109 - case of A grypnia 

 obsoleta; 110 — case of H ale sus digitatus (after Hickin). 



The building of the case is dangerous for the larva, as it prevents it 

 from moving and makes it conspicuous and easily accessible to predators. 

 The larvae therefore usually build their cases when visibility is poor, i. e. 

 under objects, in twilight or at daybreak (Phryganea). The 1st stage 

 larvae immediately after hatching from the egg are an exception; these 

 caseless, completely defenseless small larvae hatch with well- developed 

 spinning glands; some species immediately begin to build the case near 

 the egg mass; they build rapidly, in the light; the 1st stage larvae of 



65 



