36 BULLETIN 959, U. S. DEPARTMENT OF AGRICULTURE. 



each of the orchards; hence there was no chance to determine what 

 cumulative effect it might have if used over a series of years and if 

 applied to all of the trees in the orchard. Since we have no experi- 

 mental data to indicate the cumulative value of the trap the writers are 

 not in a position to make any recommendations, but for those who 

 wish to give the trap a trial the following method of manufacture is 



suggested. 



Manufacture. 



The material's needed for the manufacture of the codling-moth 

 trap are as follows: Medium to heavy burlap, ordinary black-painted 

 or japanned wire screen having 12 meshes to the inch, a folding 

 machine such as that used by tinners to fold the edge of tin sheeting, 

 and a crimping machine such as that used to reduce the end of stove 



pipe- 



The burlap is cut into strips 6 inches wide and folded into three 

 thicknesses by any convenient method. Wetting the burlap will 

 make it fold more easily and remain better creased. To assist in 

 this, however, it is well to roll the burlap up in flat rolls of any con- 

 venient size so that they can be easily handled in the field. 



The wire screen is also cut into strips 6 inches wide and of any 

 convenient length, depending on the length of the machine used to 

 fold the edges. The edge of each strip should be folded at least 

 once, preferably twice, using the folding machine mentioned above 

 or any other convenient method. This fold should not be over 

 three-eighths to one-half of an inch wide if folded once and not over 

 one-fourth of an inch wide if folded twice. It is essential that the 

 wire should be folded at least once and preferably twice, as the edges 

 can then be crimped much better in the crimping machine and a more 

 desirable bulge produced. Both edges of the strip are then run 

 through the crimping machine, which should be set to make a fairly 

 deep crimp without cutting the wire and about three-fourths to one 

 inch from each edge. This crimp will aid greatly in giving, as stated 

 above, a desirable bulge to the wire when it is applied to the tree, 

 and further it will allow for the expansion of the tree trunk as it 

 grows throughout the season. As the wire comes from the crimping 

 machine it can well be rolled up into small rolls, which will greatly 

 assist in keeping the crimp intact and also facilitate the manipulation 

 of the wire in the field. If the crimping machine mentioned above 

 can not be had, some other method, such as tucking the edges, must 

 be adopted to give the desired bulge and to keep it away from the 

 burlap on the tree. 



Application. 



The materials needed for the application of the codling-moth trap 

 to the tree are as follows: A supply each of burlap and wire screen 

 prepared as described above, a supply of slate nails about an inch or 



