CHAPTER XIX 

 INSECT CONTROL 



WHEN one considers the multitude of different insect 

 pests which attack all of our cultivated plants it becomes 

 self-evident that methods for their control must be almost 

 equally varied. However, there are a few fundamental 

 principles which will greatly aid in planning how to combat 

 them. 



First among these is the fact that it is essential to pre- 

 vent injury rather than to destroy the insect pests after dam- 

 age has been noticed, for usually by the time they have 

 been killed they have badly injured the plant. Thus it is 

 obviously important to have a knowledge of the more com- 

 mon insect enemies of any given crop and to plan for their 

 control as a part of the culture of the crop. 



In the control of insects affecting the staple crops which 

 are grown over large areas in an extensive manner, it is im- 

 practicable to use insecticides and various mechanical 

 methods which can be used profitably in the orchard or 

 garden. Staple crop insects must be controlled, if at all, 

 by general methods of farm practice which may be carried 

 out as a feature of the culture of the crop, but which will 

 fatally interfere with their development. To accomplish 

 this successfully it is necessary to know the life history of 

 each insect so as to know just when it is most vulnerable 

 and how a given procedure affects it, as may be appreciated 

 from the description in the preceding pages. 



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