1911] 



May- Flies of Fall Creek, N. Y. 



97 



dotted lines the angles of the bottom, back, sides, front and 

 cover. The laps on the sides should be folded over the cut 

 edges of the bottom and the front and then securely fastened 

 with solder. The cover may then be pushed down and secured 

 by a wire catch or by a rubber band placed about the cage. 

 When in use a stone should be placed in the bottom of the cage. 

 This will serve the double purpose of keeping the cage upright 

 and of providing a foot hold for the nymphs enclosed within it. 

 In Fig. 1 the completed cage is shown inserted in the water. 

 A represents the stone placed in the cage. 



l-'S-*. 



Fig. I. Cage for rearing May flies, showing 



position in the water. 

 Fig. 2. Diagram to show construction of cage. 



It is best not to insert the cage much more than two inches 

 in the water except where a lowering in the stream is expected. 

 Nymphs confined in this cage will naturally crawl up the slop- 

 ing side for emergence and the sub-imagoes will find an easy 

 grade on which to walk up to the light. The sub-imagoes will 

 sit on the under side of the cover, but if it be lifted with some 

 care the insects may be safely transferred from the cage to the 

 collecting box. 



