15 



The cost per tree given above is that for the material onl\' ; 

 freights, labor, cost of apparatus and repairs not being considered. 

 The cost as given on this basis will also vary with the size of the tree, 

 these estimates being for trees about lo feet high and with a spread 

 of about 9 feet. 



Summer Treatment. 



Few experiments have been made along this line. Some badly 

 infested trees were sprayed July 2, with 10% kerosene and excellent 

 results obtained, no injury to the trees appearing, while the great 

 majority of the young scales were destroyed. Enough remained, 

 however, so that by the end of the fall the trees were considerably 

 infested. Probably three or four such treatments during the sum- 

 mer and fall would prevent any marked increase in abundance of 

 the scales, holding them in check till the more thorough winter 

 treatment could be made. 



