CHAPTER XI 



INSECTS AND DISEASES THAT INJURE THE CROPS 



Insects and Plant Diseases. The farmer may pre- 

 pare the soil ever so well, he may fertilize with the 

 greatest of care, he may cultivate thoroughly, the 

 weather conditions may be favorable, and yet he may 

 lose all or a portion of his crop through the attacks 

 of insects or the ravages of plant diseases. 



Every child has seen potato bugs at work and knows 

 full well the damage they will do in a short space of 

 time. If they are not destroyed the crop of potatoes 

 will be. However, the farmer has learned how to fight 

 this pest successfully. But there are many other in- 

 sects injurious to the crop which the average farmer 

 has not yet learned how to fight, and he has paid but 

 little attention to plant diseases. It is not within the 

 province of this book to deal with these subjects in 

 detail, but there are a few general principles which may 

 be laid down here, and which will prove of value in 

 the war that the farmer must continually wage against 

 plant diseases and insect pests. 



It is necessary for us to know something of the life 

 history of the insects which we fight when they lay 



