INSECT ENEMIES OF WESTERN FORESTS 177 
spray by means of power spraying apparatus. Such methods are 
commonly used in the control of park- and shade-tree defoliators, 
but under forest conditions can be used only along roads or at camp 
sites and resorts where it is possible to tr ansport the heavy equip- 
ment. Because of the height of forest trees, high-power spraying 
pumps are a necessity. Even the largest spr aying equipment so far 
developed is not adequate for the tallest trees. 
Ficurp 85.—A long hose permits reaching out for distances of 1,500 to 5,000 feet from the 
spray pump. 
Spraying for the control of the spruce budworm has been carried 
on for several years in the Shoshone National Forest, Wyo., along 
highways and around summer resorts. One of the largest spraying 
outfits so far developed has been used in this work. "This consists 
of a three-cylinder power sprayer with a capacity of 25 gallons per 
minute through 14-1nch tip under a nozzle pressure of 300 to 1,000 
pounds. This pump is mounted on a motor truck that carries from 
1,500 to 5,000 feet of hose to reach out on either side of the road 
(fig. 85). This equipment can shoot a stream to a height of 90 feet 
when a %%,-inch tip is used. But even this powerful equipment 
136650°—38——_12 
