68 FLY FISHING AND SPINNING 



imago condition within the shelter of this retreat, it crawls 

 to the surface and finally takes flight (see Plate VIII., 

 Fig. 4). 



The best known form of this fly is the Alder. 



THE DIPTERA, OR Two- WINGED FLY 



The very numerous varieties of this class of insect pre- 

 clude more than a brief reference to those forms which the 

 fisherman is most likely to copy as artificial flies. These 

 are : The Black Gnat, the Oak-fly, the Spider-fly, the 

 Cow-dung, the Golden Dun, the Hawthorn-fly, and the 

 Claret Smut, sometimes known as the Red Quill Gnat. 



The larval and pupal characteristics of these flies differ 

 widely, and the student can do no better than consult 

 entomological works on this and the other families of water 

 insects. 



The most common form of this family is the house fly, 

 and this hardly needs illustration, but its larval and pupal 

 stages may be of interest to the reader. See Plate VIII., 

 Figs. 5 and 6. 



WHAT SORT OF FLIES TO USE AND WHEN AND WHERE TO 



USE THEM 



If possible, the fisherman should determine before he 

 leaves home what flies he may be likely to want when he 

 gets to his water, so that he may be certain of having 

 his box well supplied with those which are likely to be 

 taken by the fish. He should, if possible, find out with 

 which one he should commence his work, for should there 

 be no hatch of flies on, no flies to be seen on the water, and 

 no evidence available on this subject when he arrives there, 

 he will probably lose a great deal of valuable time ere he 

 finds out the particular one which is likely to tempt a trout 

 to rise. 



