INSECTS INJURIOUS TO SHADE TREES. 91 



The lesson of thoroughness cannot be too strongly incul- 

 cated, and it is better to be wasteful of time and material to 

 secure this, than to do much in an unsatisfactory way. Every 

 missed branch will stand out later, and to avoid this the crew 

 should be taught to work in some systematic manner, so as 

 t< i reach all parts of a tree. 



Concerning the cost of machinery and operation, no one set 

 of figures will cover all conditions. A barrel pump outfit 

 complete, with a short line of hose, rod and nozzle can be 

 had for as low as fifteen or twentv dollars, 



. . Cost. 



while a power sprayer consisting ol an engine, 

 pump, 200-gallon tank and truck may cost from fhree hun- 

 dred dollars up. 



As for the cost of operating, this depends on the size of 

 your apparatus, number of men necessary to operate it, num- 

 ber of trees and their accessibility, availability of water and 

 in fact numerous other conditions, which will not become 

 apparent until the work is under way. Where conditions 

 are favorable large trees are often well sprayed for as little 

 as one dollar each. Whatever the cost, if one succeeds in 

 checking insect ravages, he will be amply repaid by the in- 

 creased vigor and beauty of the trees. 



