378 



ECONOMIC ENTOMOLOGY 



cheap hand-pumps are usually sufficient; but for orchards pressure- 

 pumps, operated either by hand or by power, are essential. With or- 

 chards over 5 or ID acres or with high trees power-pumps or sprays, 

 capable of giving a high pressure of 150 to 200 lbs. are now generally 

 used. An important feature of all spray pumps is the agz7a/or for keeping 

 the chemicals in the tank well stirred. Moreover, it is very essential 

 that the spraying be done thoroughly and at the proper time. 



Thoroughness oj spraying, while largely a matter of personal atten- 

 tion, is secured with greater convenience with a pump of high pressure 

 and with suitable nozzles, extension rods and hose, 

 so that every part of the plant, the tips of the 

 twigs as well as the larger branches, is drenched. 



The proper time of application is determined 

 by the habits of the insect, and herein lies the value 

 of a knowledge of the life-history of the insect. 



Fig. 245. — Knapsack sprayer. 



Fig. 246. — Bucket 

 force pump. 



SPRAYING EQUIPMENT 



Outfits for spraying may be classified as follows: 



1. Atomizer sprayer, useful for treating individual plants. 



2. Bucket with force pump, convenient for small areas (Fig. 246). 



3. Knapsack or compressed air sprayer, operated either by hand or 

 by compressed air, useful in greenhouses, stables, poultry houses, etc. 

 (Fig. 245). 



