CHAPTER IV 



STONEFLIES, ALDER, SMUTS, ETC. 



The stoneflies or Perlidae are most important on the 



north - country, midland, and 

 Stoneflies. other rapid rivers, where the 



sunk-fly fisherman is more 

 often seen than the dry-fly man. 



Hints for identifying an insect as belonging to this 

 family are given in page 224, and it may be well to add 

 here that the genera and species vary considerably in 

 size. The largest of the stoneflies are among the 

 giants of British insects, and small ones like the 

 willow-fly when at rest are comparatively small and 

 attenuated flies, although these when in flight with 

 their four long and narrow fluttering wings convey to 

 the student the impression of far larger insects than 

 one really sees. 



The eggs are ovoid and generally dark in hue, and 

 are packed in a bunch covered 

 Life history. by a thin integument and en- 



closed in the tail end of the 

 body. When detached they are not surrounded by 

 any gelatinous envelope, and are deposited by the 

 female while flying at some height above the water. 

 As they fall they separate and sink at once to the bed 



284 



